In the past year I got back into collecting, after finding most of the monochrome modules at a Half Price Books in VG/NM condition for ~$10-15 each.
When I was putting them on my shelf, I noticed module
B1 was noticeably shorter than the others.
Most of them are spot-on at 11", with a few being slightly taller at 11 1/8". However, my
B1 is only 10 3/4" tall. A full 1/4" shorter than any other. Is this typical? Are all printings of
mono B1 shorter than other monos? I did some looking around this site, but didn't find any discussion on this.