Never had the Model 637 but I owned a Model 5906 for awhile. According to my book the 5926 was discontinued in 1992. Personally, I liked that 5906. It was reliable, durable, a nice shooter, and good looking handgun. It was on the heavy side but that made recoil almost non-exsistent.
I never had any bad luck with stainless Smith auto's. Had a Model 4006 also (40 cal). Another good gun. Other TFL members haven't been as pleased as myself however. You might want to do a "search" for more info. Good Luck, J. Parker