Ithaca M37 Vietnam Trench?

[K98kG43]

Unless you've tried to slip a dime in and it's closed up?

I'm not much of an expert on shotguns so thanks for the tip Jim! Never heard that trick before. Anyway, I put the Dime on and it wont go in, pretty sure it started life as a short barrel, has the hole plugged with a black material where the front sight should be, just like my 1897 Trench. Think this was a riot barrel that someone put a heat shield on later? Did they make Full choke Riots? Whoever did it did so a decent amount of time ago as the parkerizing has, I'd call it "browned" together and wear areas. I don't know. Weird piece. And this serial # set around 1967 seems to be " lost" at Ithaca.