To the uninitiated, the model 17 was the predessor of the Ithaca 37. It came in 20 gauge only, and was more petite in the receiver than a later 20 gauge Ithaca model 37. It never sold in the numbers that the model 12 did, and has a simpler takedown (only the barrel itself is removed, and it can be done with one hand) and bottom ejection, and load. The benefits of bottom ejection and load are mostly theoretical, except in a duck blind, or, if you are left-handed. I've owned all three, and have sold copies of the model 12 and 37 (a couple just recently) but NEVER a copy of a model 17. I never would sell a decent 17, either.
They are simply, that good.
Best,
Ted