Some time ago I was cleaning two Mod. 34-1 revolvers and removed the side plate from each one. I noticed the rod over which the mainspring is installed was different on each one in the way they connected to the hammer, one has a fork on the hammer end and the other has a round knob, yet they were both 34-1 revolvers. This difference constitutes a big improvement in the smoothness of the two trigger pulls. (This make sense?) I prefer the round knob as opposed to the fork type for that reason and wondered if this is identifiable without having to remove the side plate? Did I miss something as far as an Engineering change? Thanks, Sam