Conclusion.. still not sure.
bought 2x pc75 finals from Alibaba. They we're hard to ignore priced at $600 each with 'free shipping'.
The free shipping was a misprint. Cost an additional 800 to ship from china to Tacoma.
The port fees cost another 1300 to release from customs.
The finals fit well, and look nice. The finals were not exact replicas of the hy dash units it came with. I'm not even sure they have the rolley pins in them? I think may just be planetary setup. They are 2 speed units. They also used sae bps vs metric. So now I have a bunch of adapters to fit the hoses.. another 250.
As long as they last another 3,000 hours will be well worth it. No reason to expect they won't. Will update if one blows up.
Moral of story. The price on Alibaba is about a 1/3 what actual costs will be, once you've got it and it's spinning again.
The people in china were very responsive and not hard to get in contact with at all. Had some bank transfer issues at first which kinda left me un protected for a couple days. They didn't take advantage. Once I got units in and tried to figure out best way to bypass 2 speed port they again were happy to help, even send free parts if needed. They suggested to jump from drain to speed port rather than plugging. Offered to send fittings and hoses if needed. Better than some local customer service..
The big test remains... Will they last? Hope so!