the door will be toast with water rot from water getting in from the window. You may find one on a slide in truck camper. I built a new one from a wooden interior house door skinned with formica and put in a round porthole window. I think I would try to find a proper door if I were to do it again. BTW if the lock is in good shape , it will probably sell for about $200 on ebay, its a Bargmann l400 so there is half the cost of the trailer. The nice thing about the Ventura
is that it has flat walls so makes the interior work fairly easy but it does have weak roof formers that break due to snow load and the roof will sag causing leaks
. Also check for cracks above the rear window as there have been a few reported here that go right through (including my old one). The top and bottom halves are NOT fiberglassed together and may be leaking so add that to the list.
There are a few here that are going through rebuilds this year with lots of pictures!
They are a fairly hard tow as the have a flat high front end and cause a lot of drag at highway speed compared to say a boler
, but they also have a stronger frame and brakes(if they are working)