I would not be afraid to open carry on a horse dressed up like a cowboy where it's lawful to do so. People are so accustomed to seeing cowboys with guns from decades of film and TV. It wouldn't be more shocking for most to see a modern-day cowboy with a gun than to see a uniformed cop with a handgun in a holster or a uniformed soldier with a rifle.
In semi-rural northern California, my boyhood town of Novato, a butcher came in a truck to slaughter a neighbor's cow circa 1969. A few neighbors had horses for pleasure and a couple head of cattle as individuals for personal meat. Some goats and sheep were kept as pets. But I digress. The man pointed a pistol at the Hereford steer and fired next door. He was about 15 feet in front of the animal. The gun went BANG! The funny thing is, I can't recall seeing the animal drop when the gun went off. My mother in a distressed state suddenly got me inside the house and kept me there until the truck left. She was raised in the city. She was not hip to the common goings-on with domestic animals for slaughter. She did not want her five-year-old boy to witness this kind of operation. How young were you when you first witnessed a livestock slaughter? My mother hated hunting also. She would eat store-bought meats though. My parents did own two handguns for security. A Smith & Wesson police .38 Special and a Beretta Minx purse gun.