Can this 8" Sponge Rubber disc be used with a Crystalpad on my CabKing V8 cabbing machine? If it can be used - how do you attach it to the machine?

Yes you can use that. If you order the one that says PSA, you will be able to peel the backing off and just adhere it to the master spin on disc. From there you can peel the backing off of the Crystalpad and adhere that to the sponge rubber backing.