In addition to producing the 1954 and 1955 paper inserts for four issues of Sports Illustrated magazine, Topps produced what I believe to be a 40 subject sheet of baseball stamps that were never released to the public. These were direct copies of the 1955 Baseball cards that were perforated on at least one side and had gummed, blank backs. A sister internal sheet of the same year's Rails & Sails stamps was also produced, which was, you guessed it, 40 subjects long.
The known checklist is 24 subjects, 23 of which have been sighted and/or previously checklisted by Beckett or the Standard Catalog.and are listed below. All appear in both the regular Topps issue plus the Double-Header set as well and I've included the corresponding numbering for both.
The 24th subject is Hank Aaron, "confirmed" by some prominent hobbyists but not yet in scanned form or on the major checklists. It is thought all of these came from Woody Gelman's personal collection. In addition to the Rails & Sails stamps being 40 in number, another reason I think this set is also comprised of 40 subjects is the way the regular issue cards were laid out. The usual orientation is off because of the horizontal printing but you can see where all subjects were taken from a chunk of the 110 card uncut sheet that runs from columns 2-5 and down rows A-E. (U) means unconfirmed of course and Hammerin' Hank gets an asterisk):
Some observations are in order. There is another 40 subject section of sheet real estate that has Wally Moon at B5 and Hank Sauer at C5 but since both those slots are occupied by confirmed stamps, I think this is the proper array. As you can see, each row and column has at least one confirmed stamp as do all "borders" so the 40 stamp universe seems highly likely to me. And that lower right corner, which is an entirely missing quad-save possibly for Aaron-can you imagine what a Ted Williams stamp would be worth?!
Two of the stamps made it into REA, Jack Shepard and Bob Skinner. I was underbidder on the Skinner (a PSA 1) but didn't go after the Shepard (a PSA 3). I'm showing the backs so each can be identified in the future if another comes up (it's not 100% confirmed but there may actually be two of some subjects out there in the wild).
The lot description has that little curl at the bottom of the Skinner reverse as "excess paper." The ink spray and off-registration on the fronts doesn't surprise me as I think these were a materials test as Topps was very much putting a lot of effort into alternate media at the time, something that was killed off forthwith once they purchased Bowman in early 1956.
Ironically, the first mention of these I ever saw was from a Rob Lifson ad in the January 31, 1986 issue of Sports Collectors Digest, where he had four for sale. I am hoping more pop up down the road as I would very much like to have one for my collection. Kudos to whoever won these!