I got called out for a rekey the other day and came across an interesting specimen, unusual for North Seattle. I don’t know what company manufactured it, just that the keyway was Challenger HO1 (so it was probably Challenger). To rekey it, I had to remove the whole lock off the door, something one need not do to rekey knob locks made in the last twenty years.
Once the whole assembly was removed in one piece from the door, it was time to remove a copper cover plate. Then I had to remove a cotter pin. Then a silver piece of metal that covered two more pieces of metal that retained the inner and outer knob. Once the outer knob piece was removed, I could pull the knob out. Then I had to drift out a roll pin to get at the cylinder. Finally a familiar sight: I took the plug out and rekeyed it. Putting it back together was harder. The knob didn’t want to go back in because of metal pieces that were in the way and difficult to manipulate, but once it was in and all the pieces were thoroughly tested, I put it back on the door with a latch protector (it was really easy to open this door with a credit card, there was no deadbolt, and this was the cheapest way to let the beautiful old lock remain in service). It only took 45 minutes to rekey but what a specimen!