SRX250 was only brought into the US in 1987, only one color. Guess nobody even knows about this bike.
There will be tanks here in OZ , but I'm not sure about sending a fuel tank O/ S though. The USA tank have a different fill cap assy and also you have a vent tube fitted than our OZ supplied tanks. Personally the USA tanks do look a lot better. I was aware that one wrecking yard had one a while back , I can ask if you'd like.
There is an SRX tank hung on the wall next to the window in this Craigslist ad https://myrtlebeach.craigslist.org/mpd/d/conway-salvage-motorcycle-parts-of-all/7169721631.html