That collaboration is what produced the
380 Govt Model, which Colt then "chopped" to make the Mustang.
I remember reading about the Colt "pony" 380 many years before it actually saw producion.
The DK was a 6" long, 15 oz 380, with a locked breech, that was being shipped to the US in the '60's. GCA 68 banned its importation, but they can still be found, for about $400. There were far more of the steel framed model D "pony" imported. First, the frame was made by Iver Johnson, and the parts were imported. then Firearms International took over.
I don't recall there being any .32 Colt-star types. Colt had a Browning type blow back .32 for a while, back in the 30's or so. Patton used a version of it. In the movie,he fires it at an attacking German plane.

The Colt was a simple blowback, the Star and the Mustang-Govt models have locked breeches. This lets you load them about 50% hotter than can be safely done with a blowback, but no ammo company dares do so, for fear of being sued for blowing up a blowback 380.