Given the scarcity of any S&W with King goodies compared to Colt I'll look long and hard at one.
I think you're right about the white outline rear that KIng was doing in the 30s but wasn't King gone before S&W made a big deal of w/o?
I've got a Colt .22 Bankers Special with King front but the old S&W "fine tune" rear. Just saw an SAA yesterday with the same arrangement
As I get older and more forgetful, I need to go to my files more often and right now I can't do that. For somewhere within them, I assembled a time line of sorts from all the various bits and pieces I was able to collect on who made what when as well as how King was listed or shown in the simple box-like ads or entries that I think was about all one saw in terms of self-promotion.
As I think you know, Smith not only sold them guns (and possibly bought loose sights in return, although at the moment, I am not 100% on that) but apparently shipped them guns to have sights fitted and returned. I believe that at one time, most, if not all, of the red insert front sights (usually, but not always, with the mirror as seen on the gun in that Ruger thread) were King's. And not too long ago, I helped a friend out with a rather unique Non-Registered Magnum that employed one of their ivory (or ivory-like) front sights that was matched to one of their white outline blades installed within the Smith factory rear sight assembly.
Personally, I've always felt the hot setup was the half-circle, white-filled groove that King apparently cut into the frame and around the factory-milled rear sight notch on both fixed sight "K" and "N" frames but I digress.
If I remember correctly, this vendor-manufacturer relationship took a hit when Smith, not necessarily in need of the reflector sights but certainly seeing some value to the pinned red insert types (you can see the pin in the photos contained in that Ruger thread), decided to start doing something like that on their own.
What is interesting is that you are right: all of the King-related work and even a lot of the early Smith stuff existed in an era when I don't think many people were into either red front blades or white-outline rear ones; especially
the white outline rear ones.
For while people had long used ivory (white) "beads" as well as gold ones, brass ones and brilliant stainless ones (the latter being available in at least two forms that I can think of, offhand), which either sat on top of a post or were set into or on to the face of one, the employment of the square kind of insert seen on the gun that we are discussing was not as common and I don't believe the red color wasn't anywhere near as popular (or even thought of by many shooters) in the years before the war.
Similarly, for all the rifle-like front beads seen on some factory target guns (primarily on the Colt's) and the numerous flat and raised beads one finds installed into the Patridge-like front sights on many Smiths, the rear blades, while sometimes pretty creative in their own right (with notches almost becoming apertures), were usually flat, not colored and generally unadorned.
It wasn't until after the war (and for the most part, I think well after the war) that Smith really started offering and promoting such things to the masses. And to be honest while certain combinations (moving toward what I think is the unfortunate expansion of the red fronts) involving the white outline rears were routinely available by the late 50's and throughout the 1960's, I don't think that it was until the 1970's that the buying public really began clamoring for such things and/or all but expecting them on some guns from the factory.
, I am not surprised that you have found the older (prewar) Smith rear sight installed into various guns from that period for not only was it available but its smaller (unobtrusive and almost delicate) shape and dimensions would certainly allow it to "fit" on to little guns like that Banker's Special as well as on to bigger revolvers like that Colt Single Action, whose contoured mounting surfaces would not have accepted something larger without radical and perhaps visually-offputting milling or other methods of installation.
Even after enthusiasts began seeing larger and blockier K-Frame rears used widely in the custom 1911's of the 1960's and early 70's, it was the smaller (kindler and gentler?) adjustable J-Frame rear that was still being used in many private revolver conversions because its smaller stature was more in keeping with many of the guns on to which it was installed.