With your Tobin No.18,3XX -
A. when locked up, does the barrel lump protrude thru the bottom of the frame?
B. what are the side plate markings?
C. regarding the recocking of the action when the barrels fall, is the forearm "recocking part" male or female?
Just for my own information, I've been trying for many years to determine when certain construction features/details changed.
I have "Woodstock Ont, Canada" address Tobins from 9,4XX to 19,4XX. My No.19,1XX just shows "TOBIN ARMS" on the side plates. Ted S had an American address Tobin several numbers higher than my Canadian 9,4XX, so it appears that Tobin brought some "work in progress" when he "removed to Canada".
The use/load recommendations from Ted S are right on the money. My 16 GA wand gets out once a year (maybe) for 'leaves up' ruffed grouse. Every several years I'll use it for a round skeet down at Golden Triangle Brockville with my low-calorie homebrew reloads.