GNRHS GN equipment diagram books - digital downloads for purchase
The Great Northern Railway Historical Society has added a bunch of digital equipment diagram books to their online company store. They are a very reasonable $4.95 each.
I purchased the 1927 freight equipment diagram book. After paying for it on the website, I was immediately sent an email with a link to download the files. Instant gratification!
The book is in three separate PDF files, one for the index and two for the diagram sheets (1-50 and 51-79). The diagram sheet files were 51 and 31 MB, so fairly big. After a quick perusal, it looks like it is a scan of a photocopy. They are black line on white background. Nearly all of the diagrams are very clear and legible, though a few are a bit light in areas and a couple are a bit dark.
Overall, I think it is a good value for the money. It would be great to see more historical societies do this.