1980-87 SSFC HOF Card
"The 1980 SSPC set was commonly known as the Baseball Immortals set. This standard-size set honored all of the members of the Hall of Fame. When the set was first issued the first 10,000 sets made indicated first printing on the back. This set continued to be issued as new additions were inducted into the Hall of Fame. Baseball writers Bill Madden and Fred McMane wrote the text used on the backs."
In Beckett's usual, thorough manner, they don't mention ANYTHING about what the set looks like, whether it was actually numbered or the physical dimensions. I don't have my Standard Catalog handy, but I'm willing to bet it's identified much more completely.
Actually, reading the description again, it says "standard-size", so I'm assuming they mean 2.5"x3.5".
Ok, how about this (from the 2006 Standard Catalog):
1995 Baseball's Hall of Famers Creating History (accompanied by a chest-up shot of Spahn)
"This boxed set of large-format (2 7/8" x 4 1/2") round-cornered cards was designated "Flash-Pack/Knowledge in a Nutshell". it was described as the first in a series. Card fronts feature borderless black-and-whte or color photos with no player identification or other graphics. Black -and-white backs identify the player, provide a career summery and date of selection to the Hall of Fame. The unnumbered cards are listed here alphabetically. The boxes set originally retailed for $9.95."
Complete Set (36): $20 NM/M
Common Player: $0.50
Edward G. Barrow
Andrew "Rube" Foster
Kenesaw M. Landis