An interesting observation. The door frame had a crack in the bottom left corner when we bought it. I had assumed it was from normal traffic over the past 30+ years, the seller was certainly no help at all. But I now know why the crack developed -- I think. The jack at the front of the trailer and the stabilizers at the rear are actually a touch too tall. They need to sit in a small 'hollow' in the ground to sit level. The PO went to great lengths to tell me that he usually set the front of the trailer on the ground and then lowered the back stabilizers on the bumper, then lifting the front and swinging the jack down. He would then proceed to adjust the jack to level. However, if you do not create small dugouts for each stabilizer and the jack you basically end up with a literal 'sag' in the trailer. The frame is fine, but the stabilizers at the back are lifting up, the jack at the front is lifting up, and the axle
is staying put. The fiberglass is moving to accommodate. It's not visibly out of line but its enough to make the door scrape in the bottom corner on closing. The door closed freely before leaving on our trip, it would bind on closing at the campsite, and closed freely when we parked it at home without the rear stabilizers down. I will use my shovel next time. Golfers, please replace your divots.
Also, the door has almost 1/8" play vertically in the hinges. Minor stuff, but I found that putting an electrical
u-shaped connector in the gap makes everything nice. I will replace it with a permanent fix using solid core wire later on.