Anyway.
That would be a K-22 Masterpiece.
First came the K-22 Outdoorsman in 1931. This was the first 'full sized' 22 rimfire revolver S&W made. There were some smaller ones before that built on the I frame, but this is a 'full sized' revolver. K stands for the K frame which is the frame size that S&W developed for their first 38 Special revolver back in 1899.
This is my favorite 22 revolver in the whole wide world. A K-22 Outdoorsman that shipped to the Providence R.I. Board of Safety in 1932. Roy Jinks, the official S&W historian told me it was probably used by the Providence Police pistol team. Do not let the wear on this side of the frame fool you, this baby is the most accurate 22 revolver I own. It has probably had a bazillion rounds put through it in almost 90 years. Still a tack driver. Notice the lack of a rib on top of the barrel and the little teeny screw to adjust the rear sight for windage. There are two screws, one on each side. You loosen one, then drive the sight the direction you want with the second screw, then snug up the first one to the new position of the sight.
The K-22 Outdoorsman was made until 1940 when the first K-22 Masterpieces were made. Masterpiece is a term S&W used to denote the micrometer click adjustable rear sight, short throw hammer, and anti-backlash trigger. The K-32 Masterpiece and K-38 Masterpiece are the two other Masterpiece Smiths. There were very few of these early K-22 Masterpieces, only 1067 were manufactured in 1940 and 1941 before S&W devoted themselves to production of revolvers for the war effort. Five screws refers to four screws securing the side plate and one screw in front of the trigger guard for the spring and plunger that move the cylinder stop (the part that locks the cylinder in position). After the War, S&W started up K-22 Masterpiece production again in 1946. This is a K-22 Masterpiece that shipped in 1950. Note it has a rib on top of the barrel and the modern style rear sight that does not need a tiny screw driver. Just one big screw on the right side. There is a tiny ball and spring inside so you can count the clicks as you adjust the sight. You will notice the hammer shape is very different than the K-22 Outdoorsman, this one has a really big hammer spur for an excellent grip when cocking the hammer for single action fire. If you look carefully you will see a tiny piece behind the trigger. This is the 'antiback lash' piece, I forget what its real name is. It is set at the factory to prevent the trigger from hardly moving at all after the hammer falls in single action fire. Sometimes guys mess with it, but my advise is to leave it alone. Both this one and the K-22 Outdoorsman pictured above are five screw revolvers, there is a screw hidden under the upper corner of the grip, and the screw in front of the trigger guard is present. This model, the Postwar, 3rd Model K-22 Masterpiece is the only K-22 that is truly a Pre-Model 17.
In 1957 Smith and Wesson changed over to a model number system of identification of their revolvers, vs the old system that used names such as K-22 and similar. The K-22 Masterpiece became the Model 17. I bought this one brand-spanky new in 1975 for $125, but I think you would have to pay a little bit more for it today. This is a Model 17-3, meaning there were some engineering changes from the original Model 17 in 1975. The barrel rib on this one is a little bit heavier than the barrel rib on the K-22 Masterpiece above. If you look carefully you will see the K-22 Masterpiece has a barrel that is slightly tapered just in front of the frame, so it is of a smaller diameter for most of its length than the Model 17 barrel. The model 17 barrel is the same diameter for its entire length. The same arrangement of the rear sight as before, but the front sight on this one has been forged in one piece with the barrel. If you look closely at the revolver above you will see the front sight is a separate piece, held to the barrel rib with a pin. The hammer on this Model 17-3 is more along the lines of most short throw hammers, without the really long hammer spur of the K-22 Masterpiece above. This is a Three screw Smith, the side plate screw near the hammer is gone, as is the screw in front of the trigger. There is still a screw hiding under the top corner of the grip. Slightly better view of the 'anti-backlash' part.
Earlier you mentioned in your quest you were considering a Model 617. The number 6 in a model number denotes it is made from Stainless Steel in S&W lingo. This photo, top to bottom shows a K-22 Outdoorsman, Model 17-3, and a Model 617-6. I purchased the 617 used because it is a ten shooter, as opposed to most revolvers that are six shooters. I was competing in a steel plate match at the time and I had to fire 8 aimed shots in 15 seconds and I could not do that with a six shooter. To tell you the truth, I do not care for the Model 617. It is of modern construction with MIM parts (we can talk about that some other time) and has the lock, which also does not cause me any grief. I just think it is butt ugly with the full length under barrel lug, which only makes it heavier than it needs to be. Also, other than that steel match, I do not need a ten shooter. That much capacity just makes me burn up ammo faster than I need to.
Another view of the three.
I took this photo earlier today before you found the K-22. It is a size comparison of the Model 17-3 at the top, K-22 Outdoorsman in the middle, and a Colt Officers Model Target 22 at the bottom. This Colt is built on the same size frame as a Trooper. Difficult to make out here, but the Colt is slightly larger than the K frame Smiths.
This photo tells the story. Notice how much smaller in diameter the S&W Model 17-3 cylinder is on the left than the Colt cylinder on the right. The slightly larger cylinder means the Colt frame has to be a little bit bigger than the Smith frame to accommodate the larger diameter cylinder.
Anyway, jump all over that K-22 Masterpiece (Pre-Model 17). So much the better if you can handle it yourself. I never, NEVER buy a firearm I have not personally inspected.