According to our ShaveWiki The New Improved razor debuted in May of 1921.
1921 N459887-N999999, P1-P679777, 1A-863912A
Does anyone know when the production sequence of the various New Improved variants ran? Were thy concurrently made or did they make a batch of Tuck Away sets and then make a few hundred Standard News and Big Fellows?
Here's a New Standard model with a 1921 serial number and older knob with knurling pattern the same as the handle.
I can't wait to hit it with the baking soda / aluminum foil!
Yes I was playing with my new camera...
Serial number looks to be; 94113A if that first number is a 9.