It's a well-known Daisy. Here's another with its Daisy air pistol inside. I used to have images of the Daisy box for it, too. Unusual design in that the strap is closed at top-dead-center as the strap passes over the grip, by snapping to the fold of the belt loop. Not the worst idea but not used by any other maker.
Daisy also made -- or more correctly, had made for them -- an Arvo Ojala licensed fast draw set:
1960 daisy (1).jpg 1960 daisy (2).jpg 1 daisy.jpg
It is said that Arvo's new-ish employee Alfonso Pineda taught Daisy to build their licensed copies. There are full Ojala rigs with the Daisy name on them (see the mark above) and the toy sets shown in the brochure. Can't imagine that they made the full sets but rather had 'em from Arvo; and the toy sets . . . not made to his patent anyway so we'll have to think of Daisy as paying for his endorsement, as Myres did with Tom Threepersons. Holsters were HUGE for children 1950-1960 while TV shows marketed the West to them and Heiser owner Keyston Bros. was the king of them all at making toy gunleather.