Spotted a couple more on eBay with Black Factory 30 backs:
1912 T202 Hassan Ty Cobb ~Rare Variant Black Factory 30~ Desperate Slide for 3rd
https://www.ebay.com/itm/306370257594
1912 Hassan T202 Tris Speaker & Clyde Engle in a Close Play SGC 2.5 vibrant
https://www.ebay.com/itm/297380564314