Isham maintains a list of antiquarian catalogs, here: http://hcl.harvard.edu/libraries/loebmusic/isham/guides/antiquarian.cfm
Catalogs are collected and, periodically, the list updated with new additions. The list is uploaded to the Isham website by HUIT staff.
This is the most recent iteration of the list. Download it, update it, send the updated version to HUIT then delete the old list from this wiki and replace it with the one you've just updated.