Due at least in part to the low resolution of the photo, the rebound slide pin is somewhat obscured, but if you zoom in it IS barely discernible just below the cylinder latch thumbpiece.

Maybe original nickel. Maybe original .45 Colt. The sights are most assuredly post-WWII, and I don't think those stocks would be original to a TL, either. I'd ask for more pictures, as Muley Gil recommended.