Tracy,
I played around with the photos a bit.
I think the Bessler SN is 11276...
I am pretty sure the Bessler gun is not the old Skinner/Shattuck gun # 11278...as the most-pronounced milling marks in the left "ear" recess that is identical on the Skinner/Shattuck gun is absent on the Bessler gun.
Here is a close-up of the chamber date stamping as well...what do you think...???
My tired eyes think I see a "1942"...not a "1941" as the Bessler ad says...but it might just be the photo...
The height of the last two numbers also seem taller than the first two numbers on the chamber date stamping...