For those that have an older Singer sewing machine (mine is a 1950's model 201), I have some #6-40 x 3/8" screws that fit the holes in the sewing machine deck for attachments. I had to order a box of them to get two for my machine. This is a size not normally used any more. I'm not sure what other machines these screws might fit.
If you want a couple of screws for your machine, send me a SASE and I'll send you a couple for free.
PM me for my address.