Replace 1970s Vintage Bottom Bracket with Square Taper?

[Archie Sturmer]

A vintage spindle may have some dimensions (not stated).
The interface dimensions would have to fit with the various adapters and other parts.

 

[Martin Bike Nut]

I found this simple solution. Sunlite makes a loose bearing bottom bracket that includes a 122mm spindle. I may be able to simply use the cups that are already pressed into the BB shell, if they're in good condition. I ordered this from my local bike shop: Sunlite BB Conversion Kit from Greenline Cycles (Chico, CA)