I am also a proud owner of some of those old JBL L100 monsters and mine are still the mains in my system. I also know what you mean about needing foam. Mine rotted about ten years ago and I was lucky to find replacements at Radio Shack of all places. They were almost identical to the originals in color and everything. Do a search for vintage JBL supplys and maybe you'll get lucky. Check with Rat Shack too and perhaps they still have access to them. Good luck. Don't those L's just blast!