Wayne,
Good trick with the nail to break up foam for removal but
personally I would still inject the resin.

Jerry,
I could always pull a light vacuum as you have described but never tried it and given the hull volume a siringe may not be enough. Usually the positive pressure from the siringe is enough.
When I was building my house I set thread into epoxy to attach cantilevered verandahs that I designed to the side of the house. It worked well but I have not seen them small enough for boat fittings.

Phill

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!