I'm reading 272XX7 on that S/N Brian. 1's have a distinct bar at the bottom of the numeral and the spacing is just right on that character for a 7.
272k puts it in definite
(sorry brain fart) six digit /26\ territory! Can't be a 2 mil as they go from ~2.368k to ~2.416k, and highest 3 mil I've seen is 3.234k.
I think this is a very good candidate! Some of the similarly numbered guns I've seen, like that 269k above seem to be less "Chu" like and more "Birch" like. What they really are is anyones guess, but it's worth a try to find out!
I'll PM you with details.
PS: Apologies for the massive hijack of your thread by the way. Your refinishing job looks excellent! If it earns Blicero's seal of approval, you must be doing something right, that guy is tough to please!