I have bought many Williams and Williams by Bachmann Trains. I have gotten parts to some of my engines from a gentlemen in Beavercreek, Ohio. His store name is: Timko Repair Depot, 349 Grange Hall Road, Beavercreek, Ohio 45430 phone 1-937-429-1461 Good luck -- railbear601
I looked at my Williams part box and found 2 black alco side frames. I think I purchased them for my Louisville and Nashville Alco FA Diesels. They are black and have one screw hole in the top of the casting.
Let me know if you wish to puchase either one.....sincerely yours.....railbear601