I've owned several N-frames from the 1950s, all of which had service or semi-target hammers that were stubbier than the target hammers that we typically think of from the 70s and 80s. None of my guns had wider target triggers. However, I've noticed over that last couple years that very often 50s 5-screw guns will have the wider target hammers and triggers that I usually see on -2 guns from the 70s. Were these wider triggers and hammers available in the 50s, or does their presence on a gun mean they were added later and aren't original to the gun?

Thanks in advance!