The cut of the Fox SBT used in all the A.H. Fox Gun Co. catalogs from 1919 through 1929 and the Savage era A.H. Fox catalogs through 1934 show a half-pistol grip. The Savage era Trap Gun folder and their 1935 A.H. Fox catalog show a full pistol grip monte carlo stock.
The only Fox SBT I've saved pictures of with a half-pistol grip is the very last one made, 400568 --
400568 02.png