I bought a bag of 1000 screws years ago from:
http://www.aaronsmachinescrews.com/These look identical to the screws supplied with MOTM modules, but are
shorter so that they work with flat rails mounted on a wood frame. The
blackness never wears off. The part I ordered is:
Item Name: Qty. 1000-#8-32 x 1/4 Machine Screws, Phillips, Pan, Steel,
Black, Full Thread
Just noticed that prices have doubled since I ordered mine. Shipping
may turn out to cost more than the screws themselves, depends on how
many you buy.