Since I am on a permanent site with a screenroom attached I can't get a dealer to do a seal tech test because the only dealer in Delaware that has a sealtech machine won't do mobile calls with it.
I have learned to do my own pressure test with a carpet dryer very effectively (search DIY Pressure Testing for Rain Leaks in Tech forum). I found 2 major and several minor air leaks in my camper and sealed them but so far they don't seem to be the source of the leak.
The screws along the gutter rail all appeared to be in tight but I didn't put a wrench on them to test them. I guess I need to do that next. I am surprised that so much water could get under the plastic trim strip to cause major leaking.