Found a great cabinet for artifact storage at Federal Surplus.
It was with the other, ordinary file cabinets, an area I don't normally look through, but I had some time to kill.
It was an old card catalog filing cabinet. You know, for the card catalogs that libraries used to have.
It was the exact same width, depth and height as a regular filing cabinet, but it had 10 drawers instead of the typical 4. Each drawer is about 4 1/2" tall, so they are perfect for flat artifacts like plaques, small to medium photo albums, etc.
The old card catalog inserts were held in each drawer with two sheet metal screws, so it only took me about 15 minutes to pull all the inserts out, leaving me with nice flat drawers for storage.
Since blueprint file cabinets are so hard to come by, I thought these might be a good substitute. I know small artifact storage is MY biggest need.