Ah - well those are even easier! Take that sash out, board up the window, have it copied by a joiner for, in our case, £60, glazed for £15, and whip it back in. That took day and a half so was a bit chilly but no biggie really.
If it's the actual frame that is coming apart then you probably do need an onsite joiner. Frames rarely do fall to bits though, it tends to be the beading and then then frames - all very replacable. In fact designed to be replenished and added to.
Parting bead and all the odds and bobs can be bought at a good hardware shop. The rope is there too.
Have a go at one, a little one to start with. We enjoyed it!! Took about 2-4 hours a window [to take them from painted shut to opening] and obviously longer to sand back and paint [still waiting....] Have 13 individual sashes so you can see why me and my glossing brush are stalling.....have a stern eye on 2 UPVc replacements that will be ripped out and replaced one of these days.
Replacing the paint-scraped, stripped back and polished till gleaming original brass fitings felt realy goooooood. Try not to buy/allow to be bought new brass fittings. They are in no way as good, as big, the right colour and so on They are so much weaker too. Refurbish the ones on the old windows or ring around salvage yards/ebay etc. It really is mega worth it.