I’d like to start by confirming that I have absolutely no technical knowledge whatsoever regarding Carver movers, but unless it’s an obscure, odd-sized Chinese made bearing, I’m sure you’ll be able to source one from Eriks (Eriks acquired BSL a number of years ago).
They have local trade counters and also an online service. If you look closely around the rim of the outer race, you should be able to see a bearing number, this would be your reference when ordering a new one. If you can’t find a number, then that would suggest that it is indeed an obscure Chinese made bearing, in which case, you may be better off trying a supplier who specialises in Parts for Carver movers.
You haven’t mentioned the age of the motor mover, but If you’re intending keeping the van for the foreseeable future, it may make sense to consider sourcing a complete set instead of just a single bearing ?