While John Wayne used many Colts in his movies. One of his personal guns, Wayne gave the Colt to Gary Hess who worked for his gas and oil exploration company, DECO. The maker of the Duke's holster rig remains a mystery.
Velo-dog - Wikipedia, originated in France for bicyclist for dog attacks in the late 1800's, shrouded hammer in DA only. Originally chambered for the 5.75mm centerfire. Later models were chambered for .22 LR or 25 ACP .