I tried many different sources for this. No one has the correct case kit.
However you can buy a new complete chrome alternator.
It would be a job to smooth and polish the case.
I thought about having the case powder coated.
Took mine apart 15 years ago & had the case nickel plated. Costed around $100. Then had the alternator rebuilt with heavy duty parts. Haven't taken it off the car since & still a sparkling shine for about $150.
wow, i know they are out there somewhere. wonder where Kirbans gets his cases from. Someone makes them. hate to go thru all the trouble of taking it apart and waiting on the cases. Really hope i can find a case.