For what it's worth, not very many people have failures like this at all (I haven't read of any here) and your FX32 is rare. The John Deere compacts of similar vintage were made by Yanmar anyway, and my Ford 1700 from the same time is about impossible to find parts for, aside from basic maintenance items. I have read that Kubota is cutting back on its support of older models, too.
The imported compact tractors were not sold in the same overwhelming volume of decades-long production cycles as some of the regular farming tractors from earlier years, and the parts situation reflects that.
Frustrating as it is, the parts are at least possible to get, and there are more vendors who sell Yanmar parts than the others. Try LMTC and Sheaffer tractor while Hoye looks. They may be able to steer you in the right direction, and make your machine good for another 30 years. Some of the Yanmar components, especially for the most popular variants, are being produced by aftermarket manufacturers, so all is not lost. While I doubt the Powershift pump for an FX32 is in that category, this isn't going to be a regularly replaced item, either.