Originally Posted by till
...I can peal some of the paint off with my hands, but would like to get more off at a time...
It sounds like the PO did not prep the walls before painting which is good for you as it makes the paint removal significantly easier.
The vinyl-clad aluminum in my Overlander is pretty tough. Although a citrus-based stripper would probably be the safest, I'm willing to bet the vinyl would stand up to the more potent strippers that require plenty of fresh air during use.
Ultimately, test your stripper de jour on an upainted area
first to see if it reacts with the vinyl.