I just purchased a box of stainless steel #6 x 1/2" hex washer head, unslotted screws and have some extra (4,000) to sell
these are used on many bally/midway and williams machines from the 1980's through the WPC and WPC95 era. they are perfect for those of you doing restorations and unlike the zinc plated versions, you don't have to worry about the zinc plating flaking off and the metal oxidizing or corroding.
the cost for these are $6.00 per 100 plus shipping. I can ship up to 1,500 in a small flat rate priority mail box.