A little 37 history from Snyder’s Ithaca book. Looks like the 37S and 37T were offered with the vent rib. In 1940 they made the 37R which had a solid rib. In 1957 the 37S was dropped from the line up. In 1964 they dropped the 37T. The author says that in 1964 the Featherlight models are offered with a vent rib. So I would garner from that information the 37T was the only vent rib model from 1957 to 1964. The 37R was the solid rib. The book doesn’t say when it was dropped.
I sure wouldn’t be afraid of that 37S full choke. Briley can tube it for you or open up the existing choke. I have to say that my 26 inch IC makes a lively upland gun and no slouch on the skeet fields. I shoot it as well as my Beretta O/Us. I think Ithaca will restock it for you if you’d like a longer stock.
Last edited by mart; 11/24/21.
