[TARNATION !!!]

The top lever moves the square bolt in and out of the barrel lug. Some lugs are just the cut out and some have a T wedge pinned in place to take the wear of the friction. If worn to the point of the barrels not locking tightly the wedge can be replaced. It is more of a job to tighten a loose fit with just a cut out lug. If the spring is actually broken the top lever could feel sloppy or depending on where the broken portion is resting it could bind the top lever. Since the barrels can be removed have a look at the lug and the end of the square bolt just under the trip. Could be debris problem. Maybe a new wear wedge had been installed and not quite filed for sufficient fit. I’m a fan of completely disassembling every gun I acquire to clean out a century of grunge and replace anything in need of replacement. That is the sure way to find a problem. Good luck. Sounds like a nice find. I really like the PH guns. Cheers Jack