Going to order 2 pair of these from the link bertus supplied to ebay. Decided to get 2 extra, just in case.

I'd be wary of possible counterfeit parts - very little is manufactured in metal TO3 these days.

More modern plastic parts that will fit TO3 mounting holes might have better spec and be cheaper too.

You could probably afford to order from a reputable supplier like Farnell etc.

 

The seller I plan on buying them from claims they are old stock and made in USA. But I'll keep in mind the newer style of MOSFET.

 

Ended up ordering 2 sets of 2N6768 from Mouser. The data sheet shows them to be the same device as a IRF350. Thanks for all the help. But I'll be back with a MOV question.