That's the primary reason that I prime sensitive sections like that. Model Master Acryl is good paint, but acrylics just don't adhere that well. I'm going to be doing a lot of masking or handling I want the paint stuck. A thin coat of primer will go a long way in preventing that from happening. I don't paint much with enamel, but I like Tamiya Fine Surface Primer in rattle cans. I just take it outside to prime it.
Also, make absolutely certain there is no grease on the surface before painting. This is especially critical with most acrylics. You can wash the parts in soapy water, rinse, and let them dry thoroughly. I prefer to use alcohol since it dries much quicker than water. Water can hide in cracks for a long time.
My guess is that to remove the paint all you need to do is pick it up with masking tape. It doesn't sound like it stuck very well. Castrol Super Clean is the way to remove paint; acrylic or enamel. It will dissolve it in just a few minutes.
Painful as it may be, I'd try pulling on the bottom with some masking tape. If it sticks everything is probably OK. If it starts to peel I'd just strip it all off and repaint the whole thing. Sorry for your problems, wish I had a quick fix.