It is a type of broder. These are listable under these conditions: From the site FAQs
For unlicensed*/Broder** cards, the following criteria must be met:
- The cards cannot feature any current players as they would presumably be under current player association contracts for use of likeness.
- The year of release must be known.
- A complete checklist must be known.
- The set must be placed into the "Unlicensed" category.
- The set should have "(Unlicensed)" placed into the set's name.
So if all the players are retired, you have a fully and dated checklist (or as full as is known in the hobby) they are listable.