Mickey2

I'm guessing it's a Supermatic? You may have to hunt down parts your self, but these days there are quite a lot of help to be found with these machines. If it's a Supermatic it has a rubber friction wheel behind the hand wheel, it more often than not needs replacing on an old machine. You might be able to sand down the flat spot and get down to less hardened rubber. There are a few posts on 3D printers turning out replacement friction wheels, fitted with O-rings. There are schematics for metal friction wheels if you or someone you know have access to a lathe machine. If it's an Elna 1 (grasshopper) there are drive belts available with a bit of search.