I believe ADF Systems (Humbolt, Iowa, 800-798-5100) sells a parts washer
for ink rollers that may fit your ink-trays as well. They may also sell
filters and cleaning agents.
I've seen a printer in Lincoln with some greater than 40-inch solvent
basins, if you can't find anything let me know and I'll find out if they
bought them or had them made custom.