latheman

I am currently putting a Fortuna model G back together. On the main spindle there is a tiny set screw which I believe it was there to keep some type of shim that was used to adjust the bronze collet to set it for main shaft clearance. I have searched 2 or 3 parts books to no avail. Does anyone know what is missing and is it available or can I make it. I think a tapered like gib would probably work. This particular machine is from the early 1930's. I hope someone can help me.