Trailer ball mount upgrade

[Toolmaker51]

NortonDommi has it squared up. The earliest products tend to exceed what is currently available.
Best proof I know points to ENCO, which appear to be the first, if not largest' importer of foreign made tools. They're gone, yet used products still take in good prices at auctions. My favorites, the Dickson-style QCTP and holders and 12" V-H rotary table, nearly a combined rotab/ indexer, hell for stout. Still have my cloned Kant Twist as well...

[RetiredFAE]

Saw this same issue abut 2 months ago.
Being lazy, I drilled the tapered hole to size, then made the bushing with straight sides.