I thought that since I started this thread, I should report that today I finalized my Permatrim installation. I purchased a 3oz tube of sealant, hoping that it would be sufficient to cover all the mating surface. I applied about 1/3 of the tube and figured that, when the 10 bolts were tightened, the sealer should spread over the entire surface. If I had applied 1/2 half as much I think it still would have been twice what I needed. It took 20 sections of paper towel to wipe off the eccess; that was after some had already dripped on the ground. But a final wipe off with mineral spirits left everything clean and any gaps between the surfaces tightly sealed.
I used one of the 3 sealants suggested by Permatrim and was careful not to overtighten the 10 bolts. I decided not to say whether I used 4200 or 5200 since I had received so many reccommendations for one or the other. Central freezing Fla weather is due to warm into the 80's toward the end of the week and I am anxious to make a 2-3 day trial cruise on the St Johns River.