Sibling and I have different approaches to clearing our parent's house - difficult!

I helped clear out my daughters house when she sold and moved in with her boyfriend who already had a full house of furniture etc. Apart from a couple of items she wanted I advertised a full house of stuff on marketplace (daughter works long hours and I was helping). Her furniture was less than a year old, very modern and top quality. It was like new as she had spent more time at her partners house. As an example I sold a 4 grand leather suite for 300 and 1500 bedroom furniture for 250. Both advertised for more but no takers. Basically she got sod all and I also ended up freecycling quite a bit as no one wanted to buy and the house completion date was looming.
If your mums stuff is dated and used then I think you will be lucky to get anywhere near what you are thinking. You will end up having to give it away. The whole experience was soul destroying and I was distraught she was getting so little. (I had wanted her to store them just in case but costs were high and there was no guarantee they’d fit into any future house)

I'd add my aunt passed away à few years ago and she was a hoarder. We spent days sorting through stuff and my step dad decided loads of stuff was valuable (antique french style stuff) and i kid you not it look literally years of car boot sales to get rid of most of it. They still have a couple of pieces in the garage along with fancy plates and glassware that no one wants. Luckily they have space but it was absolutely a PITA to get rid of it.

No. I don't think you read my post fully. I was advocating just doing the charity shop and dump runs that weekend, and arranging for the auction rooms to take the rest, rather than take them to storage and sell them yourself.

Also if hiring a van at all, I'd pick one up from your mum's town.

But otherwise, I'd sit down with your brother and spell out how time consuming selling on eBay is (whether by post or by pick up), how much storage costs are (horrific, in my experience) and how little your mum will end up with, whatever you opt for. And hope that he'll eventually come round.

Your update demonstrates that you've done far more than the paragraph I quoted implied. I assumed he'd done all the house sale stuff too. So I take some of my post back.

I'm the sibling furthest away, while my DB is local to my mum. I'm only too aware of his load compared to mine, so I do everything possible that I can do from two hours away. But I'm definitely the lucky one. So I might have been projecting.

Is it a sentimental thing for him? His mums belongings? He may feel uncomfortable about strangers rooting through it. Perhaps that’s his worry and it feels like something that should be more personal to family?

If you hire a van to go to the tip, you'll have to use the trade tip. Or at least you will where I live.

Just consider going in a hire van to the tip / recycling centre ?
Doubt you'll be able to get in ?

My grandma went into a home fairly recently, and clearing her house for sale was a nightmare. It took all three of her children, two of their partners, and one of her adult grandchildren (muggins) to get it cleared and it took days and days, at least one skip and god knows how many tip and charity shop runs. They did sell a few items on eBay with mixed success - two riser recliner chairs went pretty easily and the guy collected. Other bits, less so. It was also hugely emotional as grandma had indeed saved every card, going back to the forties…! I don’t know what happened to most of the stuff. We took a bookcase and a few bits and bobs. But I suspect the vast majority went to charity.

It’s made me determined to ditch stuff before we get to that stage, and also to get a firm in when the time comes that I need to do the same job for my parents.

Had to do a clearance a couple of years ago and didn't have the money to pay someone. Listing a few things for free on facebook marketplace led to people turning up with vans and taking a lot more. Including old broken tools for scrap metal etc. Things like the dining table and chairs with fire safety tags were picked up for free by a charity. I sold a few bits on ebay. One that had to be collected and the rest were small collectibles that could be easily posted. Then a skip for anything that was just junk.

People definitely pay less than you might think, unless the furniture is fashionable like g plan or ercol. I remember before the relative passed away him saying things like the stereo is worth a lot, but everyone streams music these days. Might be time for a gentle reality check with your brother. You could look up similar items on ebay to show him sold prices.

DM has two pieces of teak mid century furniture worth I reckon £300 to £400 each from what I have seen online.
They'll go. You need more than one bidder.
If you are near a densely populated area, that will help. I would be looking within a certain radius from where I live.

Why don't you let a charity empty the house and sell anything and keep the profits? You could say that's what your mum would've wanted.

This. I spent 2 days clearing my grandads house with my aunt (in her 60s at the time) as an able bodied 20 something with no dependents. It took two days.

we cleared:

the paperwork (checking through for photo albums made in notebooks, his war record, and shifting what we’d actually need (records of savings, insurance plans we’d need to get cancelled after sale etc.)

Then clearing through knick knacks and jewelry and things like all his sheet music and dividing that up between family members who couldn’t travel but always wanted great aunt’s wine decanter or the portmarian. Appreciate it seems you don’t have this bit but you do have the paper!

and like the person said above, the food and the garage stuff.

Then the clearance company did the furniture. Can’t imagine doing the furniture at the same time!

Will you be able to go to the tip in a van?
Around here you need a permit in order to go to the tip in a van, which you have to get from the Local Authority. You are unlikely to have a permit/ be able to get one in time for a van you are hiring for a couple of days.

Check sold prices on ebay
you would be surprised what 1960s and 1979s furniture sells for

It depends on what it is, the condition and the brand. Ercol, G-Plan etc can do really well.

Very interesting

I would have thought the valuable furniture isn’t worth anything -maybe phone the auction house to check.
And estimating 2days - probably will run over that -3ofusemptied DMs house in a day but she was not well off -nearly all went to tip then a few bits to second hand shop which were both a 15 min drive away.

Clearance company all the way, unless he will be doing the online selling (which you said he won't)
Clearing out my parents' house was painfully slow.

I recently got over £2000 selling my DMs clothes- mostly on Vinted.

Check sold prices on ebay
you would be surprised what 1960s and 1979s furniture sells for

What age is the furniture?

You can absolutely still have that time going through the personal/smaller items OP, house clearance comes in once that stage is done to take what's left.

I'm an only child and had to clear out a 3 bedroom house when my mum went into a nursing home with dementia. I went through everything myself and randomly discovered £200 in cash that she'd stowed in a potato peeler machine that was part of a kenwood chef.
My mum didn't like clutter or ornaments but did like to keep all paper work including my p60's from my Saturday job in Woolworths from 1977. I spent days just shredding stuff but I took all that home to do. The British heart foundation took all of the beds and the sofa and matching arm chairs. It would have been s lot of hassle to try to sell them and I would probably have got next to nothing although they were all in good condition. They came when they said they would, and after checking the fire safety labels on them we're delighted to take them. They contacted me later to say how much they raised for the charity. As my father had a heart attack at 42 ( which he luckily survived) I was happy that they could benefit.