You just need the stat, correct, not the whole housing? The stat is held in by a rubber ring. The stats rarely fail when they get stuck its usually a piece of rust keeping it from closing. Try testing it in a pot of hot water, take a coat hanger and bend it so the stat is suspended in the water, if it starts out closed and opens at approx. 160-165 then its good. If you buy one buy 3 instead with the gaskets and a couple of rubber rings so you have spares. If you have a VP dealer in your area just go there and buy it, they used the same one as OMC for many years.
the internet has made people forget that guess what?
there are actually local dealers that sell the parts you need!
I patronize 1 particular shop nearby that can order original OMC parts from Bombardier, V/P parts from them, Merc parts and Sierra aftermarket. I usually get em in the next day or 2. Much more convenient and I have a guy with local knowledge too which is worth a lot when you are a do it yourselfer.