The standard measurements for pre-1913 L. C. Smith shotguns were 1 3/4 inch drop at comb and 3 inch drop at heel.

By the 1920s, these dimensions had changed to 1 5/8" drop at comb and 2 3/4" drop at heel.

After the Single Sighting Plane Rib became standard in 1941 (except on the Long Range Wild Fowl) the standard stock dimensions were 14” X 1 5/8” X 2 5/8”.

All stocks do not have these dimensions because the Hunter Arms Company would make stocks to order.

1920s order form; for a 2 trigger gun. The HOT form had the trigger in the middle position



Live Bird and Inanimate Target competitors at the turn-of-the-century used dimensions very similar to shooters today

Fred Gilbert (1865-1928) was one of the world’s best known shooters from 1895-1915 and used a L.C. Smith to win the DuPont World’s Pigeon Shooting Championship in 1895 and the “E.C.” Inanimate Target Championship Cup in 1896.
The “Fred Gilbert Specifications” were for a drop at comb of 1 3/8 inches; at the heel, 2 inches; length from trigger to heel, 14 1/4 inches; trigger to toe 14 1/2 inches; and trigger to center of butt 14 inches; with a full pistol grip and 30-inch full choke barrels.

Scroll down about 1/2 way for a helpful list of dimensions from a shoot in 1901
https://docs.google.com/document/d/1c7UkkNyMTZ9NAztILpzjSLKvgIneAw5i7eqkZ3d3Eno/edit?tab=t.0