Regarding the HP revolvers finished in nickel...There were 25 Model 28s with a 4-screw frame, high polish nickel finish, 5-inch barrel shipped to the Department of Public Safety, Tallahassee, FL on May 11, 1959. They were stamped FHP 32 through FHP 56. There were 54 Model 28-2s, brush nickel finish, 4-inch barrel shipped to various distributors in July 1972. These revolvers are not salesman samples.
The above are the only documented HP revolvers with a factory nickel finish.
Bill