Mystery Colt No. 1 solved, how about Mystery Colt No. 2?

Mystery Colt solved by Jim Watson, senior member at TheHighRoad.us.

Parts gun in a big way.

Frame:
Colt sn 13719 was made in 1912 for the US Army. Therefore it is, or was, a true 1911.
The stamp over the magazine catch is WGP for Major Walter G. Penfield, chief inspector for military production at Colt from 1911 til 1914.
It would have had a big bold "United States Property" stamp on the left side in front of the slide stop. That has been removed to sanitize the frame and disguise the fact that it is stolen government property. Don't worry about that, the FBI and BATF don't care about the origin of a gun any more as long as the serial number is still there.

The finger thingie on the frontstrap was welded up, the rear tang ground to take a beavertail grip safety, an aluminum trigger with holes was installed, and Pachmayr grips added, slit to clear the thingie. The arched mainspring housing looks like a Pachmayr but I would need better pictures to be sure. Hammer is a flat type much newer than the frame.

Slide:
I can't read the slide markings, you say it says .38 Super but has a .45 ACP barrel?
That was a lot of work.

Besides that, the rear sight is a Smith & Wesson revolver sight, which is kind of a gunsmithing chore to install.

Next question, call it Mystery Colt No. 2: What's up with the other .38 Super 1911 in the double auction? It has the 1911 flat mainspring housing, but it has the scallops behind the trigger, which is a 1911-A1 frame change? Serial number is 163679.I'm all ears.