Take a stud finder and see if you can figure out what is above the door. RV walls are not like stick house walls, so the door frame may not be load bearing - in any direction. From the way I have seen Holiday Rambler constructed, the frames did not have any relation to the window and door locations. That could easily be more so with laminated construction as was done by Fleetwood at that time. I have to think as long as you are away from the roof radius, there should still be another structural piece at the start of the radius where the wall meets the roof.
