rust and more rust

Repairing lots of rusted bits on this 881d I'm converting to a tiny home. The metal was very wet on the inside of the body, which leads me to suspect leaky window seals etc.Anyone have any idea how I would check and where might be biggest suspect? Also what to do about it. Kind of pointless...

Need some rust repairs near subframe mounting, and other common areas. Has anyone got any recommendations for who can help? ideally in the North East, It’s a camper with a good spec so I’m keen to keep it on the road. Any suggestions or help would be appreciated

Just interested out of those that own MB's ,who actually drives one for a living or just the occasional time,I myself drive a mercedes sprinter c311 for a living,owned by the company i work for,and must say greatest van i ever had the pleasure to drive(especially the new ones with traction...