That Turner gear box is likely from a moose-sized Turner lathe from after 1932. The company is still around in Kansas City as the Blue Chip Machine Co. They make among other things the "Turner U-drive" continuing the Turner business for 78 years making non-automotive "speed changers".
So that gear box is the real deal not from a car tranny !!! Being real American it uses inch spec fittings and seals.
Your polebarn-shop is looking great moleman !!!!