Not that I would tend to be critical (yes I would). Trying to turn that gun into a regular "Cattleman" would be a waste of time and a lot of money. Sort of Oxymoron. Taking a nice SA, safe with six, and turning it into an "unsafe with six" just doesn't make sense. For of like the folks who go out and buy Rugers then send them out to be "Coltized" at great expense. Understanding, of course, that kind of thing really added to my bottom line.
My suggestion. Call VTI and see if you can get replacements for the screws you buggered. Or repair the screws you buggered. Also ask VTI if they have a schematic for your gun. Then, while you have the gun apart, polish all the mating surfaces, de-burr all the sharp edges and put it back together. You may well be surprised at how well it will run.
Oh, almost forgot. The machine work necessary to fit standard SA parts will cost you more than a pair of those guns, tuned.
Coffinmaker
PS: PLUS ONE to Major 2