Camper Virgins - Help!

PearlJ

Hi everyone - Would appreciate your sage advice. We are complete camper virgins but are looking to purchase. We rented one out last summer and loved it and now want to invest in one. We've been looking for months and finally found one we love, but it's being sold privately, which makes me a little nervous as I always thought we'd buy from a dealer to have a little security, but we love this particular camper we've seen and it's in our price range. Seems like a good deal too with solar panels and all alarms, gas, fire, carbon monoxide... Only concerns are that it doesn't have an RGi cert - Owner claims he doesn't need it as its only a camper cooker which I know is wrong (... or is it?). I'm just terrified of buying a lemon. We've researched on what to look for when checking it out i.e - Damp in cupboards, warping of any surface and up on the roof for any signs of leaks.
With all of your experience - is there anything else we should be mindful of? Much appreciated.

Moomat

Is it a home conversion or factory build? Gas can also be used to heat water and/or for interior heating.