The back of the 1980 set has a nice shot of the steel master plates. The other images are from the covers of the 1981, 1985, 1986, 1987, 1988, and 1991 editions.
We also had a few printing house publicity materials that have wonderful photographs of the printing machinery in action and some text explaining the process:
A page out of From 'the Mystery and Art' to the Skill and Technology of the Harrison Group.
Title: From 'the mystery and art' to the skill and technology of the Harrison Group.
Author: Harrison & Sons (Printers)
Publisher: London : Harrison & Sons (Printers), 19[7-?]. 20 pages.
And from Enschedé: Printers of Banknotes and Stamps.
Title: Enschede : printers of banknotes and stamps.
Author: Joh. Enschedel en Zonen
Publisher: Haarlem, Netherlands : Joh. Enschedel en Zonen, 19[--?]. One page folded.
And from The House of Questa.
Title: The House of Questa.
Author: House of Questa
Publisher: London : House of Questa, 19[6-?]. 8 pages.
Two books on Kuwait postal history were moved from the ephemera files to the stacks:
Iraqi Occupation of Kuwait (1990-1991): Prologue, War, and Aftermath (philatelic exhibit) authored and published in 2006 by Mashael A. Alhajeri (one volume, looseleaf) for the Inter-Asian Philatelic Exhibition.
and
The History of the Postal Service in Kuwait, 1775-1959, by A.N. Donaldson and published in 1968 by Jal Cooper. 1 volume, looseleaf).
If you're interested in the postal service of Minneapolis or St. Paul, we now have several issues from 1997 - 2011 of Beyond the Stamp, a newsletter published by the Twin Cities Postal Consumer Advisory Council (now apparent;y known as the Twin Cities Postal Customer Council).
Finally, space collectors and cachet aficionados may want to check out Moon Landing: Scot C76 Cachet Catalog by Monte Eiserman and Harry L,. Anderson, published by American First Day Cover Society in 2014 (95 pages).
