Post 1460PD  Projection Versalog
Estimated date: 1950s

This specimen sold on eBay in July 2018 for $113.61 but "1460PD" never appeared in a Frederick Post catalog.  I believe I inspected a different specimen of this device about 1999.  My memory is that it operated more or less on the same principles as Post model 1460DP but was larger and used glass instead of lucite sheets.  On the specimen I saw, the tick marks and other information appeared glued to the glass surface and projector heat had loosened the glue, allowing the markings to shift position.  The result appeared like a slide rule designed by Salvatore Dali.