It was also an Ebay purchase, back around 2005. All the brochures inside are dated 1948 or older, and I can imagine a Monarch salesman taking it in to give a presentation, or maybe they gave these to big companies like GE. Many of the lathe brochures are for older models that I have never seen, like the Keller and Shapemaster, plus all kinds of 10EE derivatives (speedi-matic, mona-matic, uni-matic, 10" turret lathe, 10" toolroom lathe, 10" mfg lathe, 10" mfg lathe with turret ), the M, N, NN, NN with faceplate-drive headstock, special cost-cutting lathes (like the WWII lathe with a 40' bed for machining periscope tubes), plus all the model 60's, the 70, model KK, the mold-maker's toolroom lathe, automatic sizing lathes. The accessory brochures are for micrometer carriage stops, tool cabinets, oval chucks, tool posts, feed stops, tailstocks and centers, anti-friction-bearing taper attachment, tool rests, universal relieving attachment, sub-headstock, power rapid-traverse, cross-feeding bed-type turret, oil pan and coolant pump, automatic driver, steady rests, chucks, turrets, multiple-indexing face plate, air tracer type B. I think model C lathes were on the way out at that point, because the only C brochure is the "Features of Model C Lathes" brochure, which is 28 pages. There were no product brochures for model C lathes except the one that was named Mold-Makers toolroom lathe.
It's mind-boggling to think of the amount of engineering done at Monarch, as well as the amount of work to support sales, printing all these brochures, etc. Even though the brochures are almost all from 1946-1948, I could not find a single photo of a round-dial 10ee in any of them, all were replaced with square dial machine photos.