Fender offers casters and the snap-in socket for these amps. you can find them at Antique Electronic Supply...P/N P-HW015 for each caster & socket. Once the mounting holes are drilled in and the mtg screws installed, the casters 'snap' into the socket, so they can be removed. Or, you could have a cradle made using better fixed casters on it, so the amp sits into the cradle, and no modifications req'd to the amp. I'd probably go that way if it were me.