Vintage wet bath seal

[thinktankair]

I had to replace the bathroom floor in my 1961 bambi. All the bathroom components are out. When I reassemble the bath, what is the best way to seal the gold trim airstream used around the fiberglass? It currently has some rock hard dark caulking I need to remove. Should I put silicone on the backside of the trim and rivet it in? Install it first, then put down a bead of silicone? Thoughts?