Nice catch there Evan, and well done your friend.
Geo, the build of the Mustang is more or less out of the box, with the following exceptions:- some added internal detail, port rear window and camera port opened, scratch-built camera, added canopy runners and 'Malcolm' hood from the old Monogram kit (the ICM part is just a tad to small to fit properly over the fuselage spine in the open position). Decals from the spares box and home made. It was one of three photo-recce P-51s hurriedly pressed into service around D-Day, all finished in PRU Blue.
The kit includes the Macolm hood, and the original, framed hood, but the latter is in the closed position only, whereas Tamiya provide open and closed for this, but closed only for the Malcolm hood. There are also two styles of seat and exhausts, and lots of other 'extras'. A nice kit, also available, at a bargain price, with pilot and ground crew figures, as well as individual kits for USAAF and RAF versions.