Hi Graeme
You are absolutely correct to search with the exact p/n!
I have no objections to the garter filter but the RAPCO RA2H3-2 is different from the original C482001-0101 used on the older 150s. Different size, fittings and would require some modifications to the hoses....making the install a bit more involved.
There are several on e-bay and in the salvage yards (and apparently Cessna even has a few new ones in stock)
Thanks for your reply!