WoW!!! Incredible as always!!! I'm on my phone, so not as large an image, but the pencil marking on the 54 looks VERY similar to the Gilboy "G" penciled on many San Francisco copies, except for the fact that the bottom of the letter isn't fully closed. Given the nature of how they'd have likely been hastily marked, it might indeed be a Frisco. The Riley ink stamp on the back covers were consistent thru mid 1943, with VERY few after that time as I recall, so this not having that stamp WOULD be consistent with all of my research. At any rate, it's a spectacular copy!