Working on a nice old Hamilton pocket watch which I disassembled and cleaned yesterday. The only thing besides needing a new mainspring was that one of the little screws that holds the lower balance jewels in the plate has the head half broken off so that it can't be unscrewed. I've used alum for screws on other watches but not w/ the jewel still in. I don't think alum would hurt the jewel but does anyone know for certain? Thanks.
Tom