Thanks for posting those pics Miriam! Looks like a nice 'go over' on your trailer. I see your doors do NOT have the little catches that ours has to keep the doors from opening. WHAT keeps them 'secured'??
...Wish I had more info as to how far one needs to SCUFF to get these things prepped for paint....
Latches: The drawer has a little notch in the slider. You have to LIFT UP and then pull out. The lower cupboards have stiff hinges, and the shelves inside have a lip on them. It's a little bit of a pain in the wazoo putting things in and out (not much, but a little), but everything stays secure. The closet has an interior mounted latch.
Then there's the overhead cupboard, where we keep our cups and coffee. Now I KNOW that thing rattles open and closed when we travel, but again there's a lip. If I put things in one layer only, I'm okay. If I stack things, like the time I stacked the can of coffee grounds on top of the cups, and then we hit a bad bump when travelling, like we did the year before last, then the door can swing open and launch the can across the room where it smashes against something and coats the interior of the trailer in a fine layer of coffee ground dust. Ergo, a tiny piece of dict tape to hold the thing closed while we travel. That's the only cupboard that needs it, though.
PREPPING FIBERGLASS FOR REPAINTING:
You need to sand out all the hairline cracks. It's a MAJOR pain in the wazoo, which is why the people that paint the exterior of these little units either do a poor job on them or they charge an arm and a leg for prepping them. It's not the paint and the baking, it's the sanding, and sanding, and sanding, and sanding,...
Bobbie has a good point. A good primer, that "fills" things in would make the results much nicer.