AIBU to ask where to offload a

[YBR]

1920/30 movie projector and the approx 10 spools of 8mm film?
Small tub of mercury?

Trying to clear out Dad's things (died in June) and he was a hoarder. I just don't know where to offer these things to.

eBay?

No idea, but be careful with the mercury, horrible poisonous stuff. I think you need special disposal for it?

The projector and films could probably bring you money at your local auction house if they are in halfway decent condition, or you might try a local protographic or film society or your local history museum.
The Mercury is highly toxic hazardous waste and need specialist care to dispose of. It also has some value. You could ask your local environmental health department, or your local dentist for firms that will take dispose of this for you. And make sure you keep it in a covered container and a very safe place until it is disposed of.

Maybe contact someone like this:

about.brighton.ac.uk/screenarchive/

Should be able to advise you even if they can't take your stuff.

Oh and some types of old film can be hazardous, with a potential to explode, so store that carefully too, not in the house, until you have been advised by someone who knows what they are talking about.

I am well aware of the hazards with mercury so ebay, freecycle, gumtree and so on are completely inappropriate. [In my day we had it in the school labs, but let's not go there]. I think dad was using it to sort out old mercury thermometres but I've no idea where he got it from. It's in a sealed container in a sealed bag in a locked garage. Good thought to ask the dentist though.

Thanks for the screen archive link. will investigate.