The person who suggested stainless steel alternatives to nickel plated
fasteners has a pretty good idea, I suspect.  I recently bought some
button-head Allen cap screws from Jamestown Distributors, in Jamestown,
Rhode Island.  Their phone number is 1-800-423-0030, and the fax number
is 1-800-423-0542.

They may be willing to sell specific quantities, though the items are
usually in boxes of 100.  They sell an amazing variety of stainless
fasteners as the boat building trade is one of their targets (woodworkers
are the other).  This includes stainless staples, cotter pins, and a wide
variety of stainless nuts, washers, screws, and other fasteners.  I even
obtained some wet-or-dry sandpaper sheets for a sanding board used in auto
refinishing and restoration.  I don't know about instrument refinishing,
but I suspect those who do already know about sanding boards might want
wet-or-dry sheets for their final polishing efforts.

One caution: the surface finish on the cap screws I got was okay, but not
exceptional, and would, I suppose, be amenable to polishing.  Another
caution: they weren't cheap.  But for the long run I can't offer a better
suggestion.  They have many other interesting and worthwhile products in
their catalog.  I am in no way connected to this company other than as a
recent customer.  They got my money, not vice versa!

Best wishes,

Richard Danzey