Ahh... I recall reading about this when I got the Midget (same engine). Apparently, there is an adapter to use newer filters on that, and at some point mine had the adapter installed so it can use an AC-Delco PF53. Maybe somebody knows of a handy place to get those, I recall seeing one advertised many moons ago, but I don't see it readily in the Moss catalog. Maybe Victoria British has them? I'll keep an eye out and see if I can spot them, but maybe another 1500 owner knows where to get readily.