This past summer I visited the UDT SEAL Museum in Ft. Pierce and finally got a good look at the duckbill Ithaca 37 they have there.
I came home inspired....found a early 1950's slam fire 37 at a pawn shop and went to work.....
Here is a before and after
http://i65.tinypic.com/atpt1g.jpg
And after with a tube extension, military refinish, and a functional duckbill
http://i63.tinypic.com/1z38hfn.jpg