I've seen this topic before but can't recall where.
I am trying to fill some nagging holes in a WW collection and have exhausted Hipstamp and APS Stampstore ( eBay
Saved Searches have run dry too). I would like to use Delcampe however the searches don't appear to have search by Scott Catalog number. I can't afford to get all the SG, Yvert, Michael, etc. catalogs needed to nail some of this down. I've found a few stamps I need here but the success seems random. Any suggestions for using Delcampe? Thanks!