Well, I wouldn't be TOO jealous...after all its a dad-blamed modern centerfire...be a lot better if it was a Flintlock !

PS: I thought the use of "nuts" on the end of the tumbler shafts was certainly different, eh?
I don't recall Flintlocks and Caplocks prior to that period having anything other than hammer screws that went into the tumblers...and...haven't seen any made since that period with other than hammer screws.
As much of an overall quality piece that the Colt SxS was when it was made, I doubt Colt would have designed the tumbler shaft that way just to save a few minutes of drilling & tapping a screw hole in the end of the tumbler shaft...puzzeling