Frankly you get the cataloger(s) out of their office/cubicle/holding pen, sit the cataloger(s) down at the reference desk, and have them work from memory guidin

Frankly you get the cataloger(s) out of their office/cubicle/holding pen, sit the cataloger(s) down at the reference desk, and have them work from memory guiding people through the classification system. You won't have the same level of granularity in searching but by general subject you'll be able to get to where you're looking to go. Been there, done that, wrote the plan while I was Cataloger for a community college in an area at risk for tsunamis. Those call numbers are there for a reason and have very important meanings.