Douglas:
I have worked only on a W32 -- and fixing the leaks in the caprails is a lot of work.
I suspect that the "leak when launched" is the result of hull flexing. Further, I'm not sure that 5200 is your best choice for sealing under the caprail as I recall that it gets hard and therefor brittle and you really don't want to glue down the caprails:)
The max work solution is by Dave King and the Clarks... on Konami
12/12/16 - additions - I've started replacing as needed the caulk under the caprail with epoxy and glass to seal and level off the void under the cap rail -- then reinstalling the caprail. The life caulk just pealed off after a few years... ie leaked.
Here is another approach - not as many images but this is a replacement caprail.
John Mendoza on Marsh Duck. did a nice job of taking pictures during his job.
Finally, here is images of Pygmalion and Sundowner - this is a removal and reseal with in Pygmalions case SIS440 sealent. I also used life caulk but that broke loose from the fiberglass and leaked again.
Also look in the Members Area > FAQ and fixes for more details.
In the end, none of the fixes that I know about and that last are easy jobs - sorry.
Jay