I have two Large Advents with foam rot. These are not the ones with the
masonite ring. Looking for recomendations for refoam kits in the U.S.

My concerns are for:
proper fit, quality of foam?, and type of glue.

I used to recone Pioneer, Marantz, Altec Lansing, & JBL speakers
occasionally in the 70's so I have some experience reconing but never
replaced just the foam. I don't imagine it could be much different.