A friend of mine who has spent most of his life making and fixing things always collected broken/discarded parts to salvage for tiny screws, bolts, springs … etc.
He has shelves full of small containers and those organizer things, each with different pieces. This way he had a replacement for something … or a good enough replacement. I am always surprised when he can go over to one of the hundreds (and I am not kidding, I helped him pack/move them) of containers and find the thing he was looking for.
It’s also handy to have someone with decades of knowledge to ask.
Always good to get a hold of broken cameras of the type that you typically work on. Many use common sized screws and parts … and also other broken things with small parts.
Whenever I replace my computers (mostly laptops),the old ones are not worth it to resell, so I salvage the small parts from them. Some of these can be also be used for cameras.
One of the reason’s this Yashica repair took so long was the many missing screws (someone in the past tried to fix it) and the number of seized screws that broke while I was trying to remove them … which I needed to replace.
Whenever you can find a giveaway camera, take it … there probably is some thingamabob that you can use from it.