I've got several types of CPU and configurations in these 
nice so called "world boxes", and one of the things I've always
liked about them is there mobility.  Sadly, the casters seem 
to be subject to age, or maybe it's just that these "critters"
haven't always been stored in the nicest conditions.  With 
several of these boxes now, the casters shed black plastic 
bits on the floor when you roll the box, and that's not good.
Is there a good source for, or specs on replacement casters?

Any help appreciated,

Doug Meade
University of Maryland