Sweet boat!
Is the Gluvit on the inside or outside?
There's a product called CitrusStrip, it's a paint remover that also removes epoxy. It doesn't have noxious fumes and isn't flammable and can be used indoors. It isn't a real fast acting stripper and works best if left on overnight.
Leaky rivets can be easily fixed like this:
1989 Sylvan Boat Rebuild Part 4 - YouTube
The Gluvit is a preventive measure that should only be used after all of the leaks have been fixed correctly. Sealants applied to the outside of a boat don't work for long, if at all.
Strip all of the old crapola sealant and Gluvit off the hull and do a leak test by filling the inside of your boat with a few inches of water and then look underneath for the leaks and mark them. Replace all leaking rivets and patch any cracks. Once your boat is watertight you can apply a new coat of Gluvit to the
inside of your boat if you want... or just fix new leaks the proper way.
How does the transom wood look on that boat? Most need replacing when bought.