I also have been having some difficulty finding certain parts. I have two 16K BTU Cruiair split units that are probably oriniginal (circa 1984). They still use R-22, and I have 10 # bottle so I'm ok for now. One unit is still strong. The other has a badly corroded high pressure side base valve. The associated serive port and purge ports are all but unservicable. When I went to recharge (gauges read very low press) there is a major leak, and not surprisingly at that base valve. The main Cruisair webside was not helpful, nor was ebay or a general google search. One local Cruisair I contacted heard my plight and responded "looks like your headed for new units". That is a "FAIL" in my book. Replacement is not my first choice. He might be right, but I want the opportunity to fail first. I intend to relace the base valve and fix the leak. Hey, if I can squeak thru another season with my existing AC, I'm quite happy. If not, then I'll take him a little more seriously. I don't know if your long list of upgrades includes AC work, but if it does there may be another opportunity to wrestle with tracking down certain parts. Thanks for sharing your experiences too, and good luck!