Another option is to get the classic Corvair steering box. Since you only paid $10 for four orphan, you aen't out that much. "Vairs are getting fairly rare so the aluminum ones go for $$. However they also mad cast iron ones (stronger) with built on steering column shafts which are not in demand and can be gotten on ebaY for not much money.
The one in your photo looks like it has the build on shaft too so one of these should work. Yo do need to reverse the shaft on the 'Vair box as the drag link comes out the proper side but that is easy. See my Journal
for directions on that.
The gear in the picture (auction # 150245481970) has 5 days to go on ebaY w/ no bidders so far and is listed @ $9.50. I never go on ebaY and not find at least one, usually several of these listed.