Hi Amy,

re cataloguing (whether for on or offsite storage): offsite DEFINITELY needs complete and excellent records.

Rather than catalogue each individual map/edition, you could always do a 'series record', on a state or national basis, and include (perhaps in a 5050 field) a listing of titles and dates/editions of individual sheets.  Alternatively, attach attach  such a listing &/or a graphic index to the record. A good catalogue should be able to search xls/pdf/word files attached to  its records, or you could do the same in Archivesspace (as a finding aid in Archivesspace itself, or attached to it as a supplementary list).
Our catalogue, for instance, searches Archivesspace finding aids as well as the marc-record catalogue itself.

Cataloguing (even copy-cataloguing) every version of every 24k sheet even of a single state seems a lot of work for very little final gain over a series record with some sort of text or graphic sheet listing.  After all, most 'amateur' users know they want a map at a certain scale, but don't know the title of the sheet they need to cover their area. Others may have a citation for a sheet title, but no know what series it is from. A single series record with sheet listings helps both user types get their heads around the series, which would be impossible with hundreds of individual records for individual sheets/editions. Too many trees to see the wood!

Brendan Whyte
National Library of Australia