Welcome to the forum, Matt
I see that a moderator has moved your thread to the "Vintage RVs" sub-forum.
I really like the concept of a Rosa ...a mini-bus. First, can I ask you some questions just out of curiosity and not that it will necessarily help getting input as to your issue:
Are you in the U.S.? ...I'm kind of thinking not as we see every few Rosas in the U.S. as I personally have not seen one. ...maybe you're in Australia? What year it is? Can you give some information about the chassis ...engine type and size, transmission, etc.? Can you post some photos?
Perhaps somebody can help you out with your questions if we knew just a bit more about the unit itself.
The reason I ask if you are in Australia as I remember reading a blog/forum thread on somebody converting one there plus the fact that I know that Rosas been sold there for a number of years. eta: I just looked it up and it is in the "Caravaners Forum" from a few years ago:
Mitsubishi Rosa DIY RV build
If you don't get any help here on this forum, perhaps you can post there?