I think the list below is complete. I generated it by going to the old menu, sort on release date and copi4ed out everything down to the SD-1. There's been several SS DM-2s on Ebay but whenever I've had a chance to see the serial number, they've turned out to be replacement screws. It looks like only pedals with ink stamped serial numbers had silver screws.
Bossarea, have you seen a genuine SS SD-1? I have an SD-1 with black screw manufactured april 1981 according to the serial decoder, so there must be very few of the SS SD-1. If I don�t remember wrong the SD-1 pictured in Boss catalogue vol 1 or 2 is with black screw.
Yes, I recently came across an auction on yahoo.co.jp that I think was genuine. It had an ink stamped serial number too. Can't remember the serial but I saved the pictures. I'll see if I can find them.