Inside? Recommend rolling with lots of careful masking first. Spraying has overspray, always, and unless you mask every single thing, you will have overspray where you don't want it.
Plus you need to wear at least a dust mask while spraying, but you don't need to while rolling.
And rolling allows you to "work it in" better, in a way forcing the paint
into crevices while spraying has a tendency to skim over the top.
(Long time house renovator, remodeler, owner and renovator of a glass motorcycle trailer, Shelly, and a 1973 amerigo
, Peanut, we finished on July 3rd, 2016 after nine solid months of redoing--and former seamstress and before that interior designer/instructor, retired.
Looks like a nice trailer.
(Your Mileage May Vary--meaning this is MY opinion, yours and others' may be different.)