There are a bunch on eBay right now with Black Factory 30 backs mentioned in the item title
1912 T202 Hassan Baseball #31 Chief Waiting For Bender Thomas (Black 30) PR
https://www.ebay.com/itm/146607169662
1912 T202 Hassan Baseball #4 A Great Batsman Barger Bergen (Black 30) GD
https://www.ebay.com/itm/146607168270
1912 T202 Hassan Baseball #119 The Pinch Hitter Egan Hoblitzel (Black 30) GD
https://www.ebay.com/itm/135867812514
1912 T202 Hassan Baseball #70 Hal Chase Late McConnell Mcintyre (Black 30) GD
https://www.ebay.com/itm/135867812514
1912 T202 Hassan Baseball #2 A Close Play At Home Pelty Wallace (Black 30) PR
https://www.ebay.com/itm/146607168169