I thought that guns re-chambered by Fox were then stamped 2-3/4.
I have owned 9 16 ga Foxes. Three of them made in 1934 or later had what appeared to be factory 2-3/4" chambers.
All of my Philly Foxes had chambers which measured about 2-7/16".
Odds are that a Savage Fox with Phiily features (forend) made in the early '30's would have short chambers. From what I read, Savage used parts built in Philly for a while in the early thirties...hence the slim forend. I think savage began chambering 2-3/4" from factory no later than 1935.
