The newer Trooper MkIII and MkV have a different lock work than the Python. The Troopers made before them were the same action as a Python, as was the “Official Police” (Barney Fife gun). It had fixed sights.
The Colt “D” frame (Police Positive, Detective Special, and Diamondback) had the Python lockwork scaled down on a smaller frame. The “New Service” was made before the Python, and it was a scaled up version of the old Colt positive lock.
Thanks. I know the Trooper I tried back when was not the same as my Python. But then, nothing is.