Correct on the BASF paint but most paint suppliers do not have it anymore as it is an old style and materials to make. SO,
The last few times I wanted to paint something on the roof, antennas, a/c covers etc I went to NAPA store that has paint shop. They will match extremely close if you take something in for them to analize the color from. They make it in spray cans for your use.
Last winter in Yuma the Napa store made me some for the new storage covers I installed in front of the dual wheel wells for the new small compartment storage. They do a base coat clear coat which is extremely easy to use. Put the flat color down til you are satisfied with color then clear coat it as much as you like.
Yes it is not cheap if you compare it to the rustoleum cost but you are not doing that process on your Beaver. It is the least expensive way to get a matching automotive paint for your coach.
If you need to take a color in there are several covers, refrig vent, dryer vent, air intake vent, and the storage compartment covers that do come off quite easily to be able to let them match the color you need.
For the base coat clear coat it is about $65.00 for the 2 12oz spray cans. I have been quoted $450.00 for a quart of the BASF paint 2 years ago because that shop had some of the catalyst left so they could make it from the formula.