Need a little schooling on steering couplers

The early A box coupling isn't the same as 2 nd gen'. Parts wont interchange. Parts for the earlier coupling are nearly impossible to find. Another member was needing a single part. I don't know if he ever found it.
I have to think a universal type coupling will surely be your best route.
Do the shopping and search past threads here because obscure sources are hard to find and price range is a mile wide.
Hope this helps.