Here is more part number and interchange information for our members. My coach is a 1990 Regency with Cummins 8.3.

Fuel filler cap: I lost mine and, of course, there is no listing at auto stores and Spartan could not help as they shipped the coach without a filler neck. Did some trial fitting and Napa Cap 703-1703 fits perfectly. This is listed as fitting a 1988 GMC P3500 diesel truck.

Rear engine compartment door vinyl trim: This is the stuff that fits in the track around the doors.The best fit I could find was AP products 011351 which comes in a flat roll of 25' available on Amazon .com for $13.71. This material is fairly stiff and must be squeezed together to fit in the track. This dome shapes the middle to clear the rivet heads which hold the doors on. Careful warming with a heat gun helps a lot. Makes a very nice appearance.