If your K-22 Outdoorsman truly has a humpback hammer, then it is a later replacement. The HB hammer was not introduced until 1938, and your gun probably shipped in 1932.
The standard prewar hammer is so different from most postwar hammer styles that it is sometimes mistaken for a humpback hammer. The true HB has no depression on its upper surface at all, and the standard prewar hammer has a shallow depression. The ones in the picture are K-frame centerfire hammers, HB on the left and standard on the right. Your K-22 hammer would not have the firing pin, as those were frame-mounted in the I-frame and K-frame .22s that S&W produced. Other than that, the respective hammer profiles are identical.
Sounds like you have already made some headway cleaning up the gun, but some time spent going over it with fine brass wool and a good gun oil like Kroil or CorrosionX will be well worth it. If you can do a complete teardown cleaning at some point, that will help the gun too. But the interior flush you gave it sounds like it has helped immensely already.
Looking forward to the range report. Please post pics, too.