Well, I can't comment on the thread move.
It's an interesting observation. I have three W&Bs, an old wedge, a concave grind "Feather Edge" and a 1/4 grind and none have the "S". I haven't seriously sat down to date them but I'd guess the old wedge is from the mid 1800s, the concave grind is late 1800s and the 1/4 grind I'm not sure but probably late 1800s too if I had to guess. Maybe the "For Barber's Use" blades were different?
It's an interesting observation. I have three W&Bs, an old wedge, a concave grind "Feather Edge" and a 1/4 grind and none have the "S". I haven't seriously sat down to date them but I'd guess the old wedge is from the mid 1800s, the concave grind is late 1800s and the 1/4 grind I'm not sure but probably late 1800s too if I had to guess. Maybe the "For Barber's Use" blades were different?