Don't discout a older Model 37, they have all machined parts not unlike todays stamped and injection molded guns. I have a lighter 37 that is a joy to shoot as it functions flawlessly and if you compare it to todays junk it's a great shotgun.
If the bluing and stock finish are worn you may want to look into refinishing before interchangeable choke systems.
Here's where I get flamed, compare the 37 to a Winchester model 12, the 12 is a club:barf:, a big club, the Ithaca 37 is light fast handling shotgun.
Much better engineered then the model 12. The 12 filled a nich for the duck hunters as it was big and heavy taking up the heavy recoil of the express loads.
The Ithaca 37 is a upland game gun lighter, easyer to carry, and faster when comming up to the shoulder.
Do Ilike 37's, hell yes, my 16 gauge is one of the best pump's ever made!!