Nice find! I picked up a 5" one at a gun show about 11 years ago. Very good shooter and excellent action. It has accompanied me on a couple of multi-day hikes in Montana.
Review this YouTube video by Power Custom. Discussion of realignment of a sprung yoke. Beginning at about 1:32 minutes.
https://www.youtube.com/watch?v=XhRvNOCaWXM
Both H Richard and ken158 suggested a couple of important things to consider before looking further. Also, a "proud" pin on the hammer could cause enough drag to keep the hammer from fully seating.
Tap the hand spring torsion spring pin out by using a 1/8" pin punch and block. You won't need to completely remove the pin; just tap it out enough to remove the old torsion spring and install the new. After tapping the pin back in, be sure that the pin ends don't extend beyond the trigger...
The proper way to decrease B/C gap is to set the barrel back one turn .... a job only for the very experience with proper tooling. I'm not familiar with Uberti specs but .012" doesn't seem too far out of line especially considering the amount of work and expense to set the barrel back. Removing...