My 1950s (per registry sn estimate) TH42 came 2nd (or more hand) with a 5” BB 435 Atlas 3 jaw chuck dated 6-51. May or may not be the original chuck? Don’t know if this helps.
I recently picked up an 8” Craftsman #1111078 4 jaw chuck dated 10-2-38 in usable shape off EBay.
Good luck
