Thank you again for all of the roof sealing suggestions. I am ordering the Eterna Bond tape to do a better job next summer. For now, I seem to have stopped the main leak in my father's trailer roof with one can of the Rustoleum Leak Seal sprayed along the end strip after using a stiff brush to clean the surface of existing caulking. After another 2 inch plus rain storm, there were no more drips, but the carpet was still slightly wet. A closer look at the plastic strip covering the contact between the rear cap and the trailer side walls found places where caulking had failed, which might let water in along the wall. I re-sealed this for the winter with new caulk, and now will wait for another storm to see if any more water gets in. In the mean-time, I have dried the carpet with a small heater that has a fan. I have my fingers crossed that this will take care of the water problems. If not, I will probably have to resort to a pressure test to find a less obvious source for water getting in.
JRMunn