Well, in setting the cylinder up for moon clips, he's got it so that all three calibers work with moons. The extra gunsmithing would have been minimal. It's a sensible solution; reload speeds with all calibers would be quite fast.
Another advantage: the 45LC/454 rim width is really on the small side for use with a DA extractor star. There's a risk that a case rim could get stuck under the star and lock the gun up. By switching to moons, that entire issue is no longer a problem. Getting the extra caliber (45ACP) would be a cool bonus for free.
Why do it? In town, for personal defense, 45ACP is a fine caliber. Cor-Bon 165grain Pow'R'Balls would work great in a short tube like that. You've also got all kinds of cheap practice options in 45ACP without reloading - ammo costs for both 45LC and 454 range from high to "oh my GOD!".
As to the finish, looks like they just stripped the gray finish away and polished it up. A reasonable choice, as once you chopped the barrel and such, you wouldn't be able to re-create the factory finish on the bare stainless metal now exposed. This obviously started as a standard 454 Ruger; by the markings on the cylinder, that's stock too.
This gun really isn't all that seriously modified. The barrel is chopped and crowned, hammer bobbed, re-polished, moonclip mod and it's got what seems to be a new sight rail across the entire top of the frame and barrel holding up the front sight. Somewhat puzzling...maybe they were trying to hide the sight mount?
