Well there's painters and well wishers then there are guys that know what they're doing, lol.
FWIW, I do some painting for my livelihood. I've painted a few vehicles both with body shop equipment and with an airless sprayer. There is no way I'd try rolling and brushing a vehicle. As with all painting, the preparation is most of the work and establishes the quality of the end result. Even using the best body shop gear and materials, the surface needs to be prepared right or results will not be good.
For the OP's job, some pictures or better description of the surfaces would get better advice how to proceed. my initial thoughts from reading reading between the lines is that a thorough buff and polish may meet his requirements but that precludes any damage that is significant.
Here is an easy process to renew a painted surface or gelcoated fiberglass surface: Wash with high surfactant soap, rinse. With a garden sprayer, spray the surface with a paint preprep solution. I like to use Jasco because it's cheap and I know what it does. While the prep solution is on the surface, rub down with lightly abrasive pads, a buffer, or something that very lightly scuffs down the surface (white 3M pads). Rinse with water or if preprep solution remains dryed on, more of the same, diluted, followed with water rinse. Now you will have a surface that is clean and all the oxidation removed. For some painted surfaces you can stop right there. For gelcoat or fiberglass, I like to use extra fine rubbing compound and buff out the surface. Rinse. The final stage is applying a durable wax and polishing that out for gloss finishes. Without the wax, the above is what I do for paint prep, also.
Here are some images of my travel trailer painted with an airless sprayer and using Sherwin Williams Industrial primer and house paint along with rattle cans for the accent colors. The paint job is now four years old and is like the day it was done. This was on a 40 year old surface.
Before:
After:
Primer applied:
Finished:
Good luck with the MH. I'd definitely try the clean up and deoxidation which you'll need to do before painting anyway. If results aren't there at that point, hire a guy with airless sprayer or spray your self. Masking, especially for accent colors, is a skill and results reflect that.