Where to get replacement Rubber Feet?

here is something I found at partsexpress:
Penn-Elcom F1633 Rubber Cabinet Foot 1-1/8" Dia. x 1/2" H
Search the partsexpress website under speaker building or do a manufacturer search under Penn-Elcom.

Also, have you considered vibrapods or Herbie's Audio Labs products. Herbie's website is a good read. I am using the big fat dots (9/32 in. thick) under my heavy monoblocks, and previously used them with success under large speakers on hardwood floors.

Try Antique Audio Supply on the web.

Your local Ace Hardware store.

I'd go with Herbies feet..They seem to have it covered very well with there footers etc...Good products that are not expensive...Temporarily just cut up some small feet from and old ( hard wood ) wooden broom handle..