My 1931 vintage No. 2 Super-10 has bores of .789" right and .790" left, with .053" choke in the right barrel. While it is choke marked 4 & 4, some previous owner must have had the left barrel opened, as it has .027" choke. I owned a 1935 or later Field Grade Magnum-10 for 16 years and never used it, so it flowed down the river of commerce. My notes show it having bores of .778" right and .777" left, with chokes of .043" right and .041" left.
I bought the No. 2 Super-10 from Randy Shuman, and it has the original shipping box with the Ithaca label and the Railway Express COD shipping label showing the purchaser paid $30 down and the remaining $27.50 on delivery.