I remember calling and talking to the owner after finding his ad in the back of an old ***boat mag. I think it was at least 10-15 years ago. He was no longer producing/selling the diverter and I got the impression from our conversation there had been some sort of legal issue behind his stopping production. I think it's safe to say you would not be able to acquire replacement parts.
You should be able to buy a used Place Diverter for less than $4oo-5oo. A new one would only set you back a few hundred more.