From what I gathered on the old Walter Miller store website; the material is in process of being cataloged with an auction scheduled in 2020. I don't know if this will be individual pieces or if items will be "bundled" and sold in groups.
As for the picture itself, it is one of several for an alternative way to do the Traveler & offered to Sears Roebuck & Company in 1948 in response to their first inquiry on getting a private-labeled car for the Sears Auto Centers to sell. I've added a few more pictures here.