That cased pistol is a thing of beauty, except for the plastic jag. I'd spend a couple of bucks and get a brass one if it were me.
I have had many of them over the years, most were tack drivers as you say, and a few were, well, less than that.
If it were me, I would get different grips on it so I could hold it better, factory grips are just a bit small for my dainty hand. I have also found that a load of 30 grains Fffg, a lubed wad and a .457 ball were pretty accurate loads.
So, do we call you Two Gun Hooter now or what?