Sometimes I think people forget there's a second generation of outstanding Smith & Wesson auto pistols, and from a reliability standpoint, they have more in common with the third generation autos. At the same time, the 459, 559 and 659 autos bear more of a resemblance to the first generation 59, and that the 439 and 639 looked more like the older 39s.
What difference does that make? First, many people, me included, wanted a 59 more than its weight in gold. Fifteen shots was nothing to snicker at in those days and though they were both handsome pistols (the 39/59), neither one of them worked reliably until the end of their runs. Then, whatever the company learned was implemented in the fixes and the second generation of autos.
The second generation was flawless in operation, but a more ergonomic design was made in the third generation. Indeed, many of the parts are interchangeable between the 659 and 5906. Twenty-round mags fit both and I actually like the 659 over my 5906.
Two great second generation autos, the 645 (top) and the 659.
The 5906 had a more ergonomic grip, to some, and better (dot) sights.
The 3906.
I would hate to sell any of these guns, but all of them will eventually belong to someone else, just as yours will. Horrible thought, no? They may end up in the hands of our kids or grandkids. And they'll more than likely sell them and buy plastic autos, or worse, Apple iPads, so they can buy games and afford to text message!
.