I think that may be a legitimate 2" 15-3 into which somebody mounted a Model 19 cylinder after filing down the breech end of the barrel so it would fit. Note that the foot of the rear sight comes all the way to the front of the frame. That is standard design for the snubnose CMs, as the front face of the rear sight foot exactly abuts the rear edge of the ramp of the base into which the front sight is pinned.
The heavy rib on the barrel has certainly been filed, but the frame has been bevel- filed as well. I think that may have been just an attempt to lighten the gun by shaving another ounce of steel off it.
I don't know if the 15-3 yoke would take a longer cylinder without modification. Maybe the yoke and cylinder assembly from a 19 were installed together, in which case the length of the ejector rod would have to have been adjusted. Or maybe the ejector rod from the 15 could be used without modification. I don't know, and I am just speculating.
In any case, it is an unfortunate experiment. It feels to me as though bubba the gunsmith was trying to make a snubnose .357 with a barrel shorter than the standard 2.5" of the short M19. He also wanted it to be a little lighter. After the modifications, the geometry of the forcing cone would not be identical to what one gets in the factory M19. I would be hesitant to shoot magnum loads in this, and I'm not sure that .38 Special loads would as accurate as they would be from an unmodified M15.
I think this has potential as a parts gun, but I think you should continue to search for the original snubnose CM that you want. Selling off the action pieces and stocks of this gun would probably pay for much of the one you want. I would discard the barrel, which as I see it cannot be saved. The frame might be useless, but if the top front of the frame can be carefully milled and the sight foot reconfigured, perhaps it could be mated to a tapered barrel in case someone wanted a light-barrel target revolver.
ADDENDUM: On further thought, I think I am wrong about this being an original two-inch 15-3. As I look at the photos this morning, I can see what I could not see yesterday -- that there is a milled contour at the top front of the frame of the sort one associates with K-38 Masterpieces with longer barrels. That means I am probably wrong about the rear sight foot, but since I don't have a 15-3 to inspect, I can't be sure. I still think the barrel is a lost cause, and that there is some salvage value in the parts. I think the frame might have utility to a special project if somebody wanted to deal with improving the damaged frame contours behind the barrel.
I don't think I would shoot this gun. I agree with Model520Fan (below) it looks as though the front locking pin does not engage the end of the ejector rod, so there is no second-point support for the closed cylinder.
