The Army Special was renamed as the Official Police in 1927 and made until 1969.
Since the Army Special has the same frame size as the Official Police, original Trooper and Python, any holster made for an original Trooper (NOT Trooper Mark III) or Python will fit the Army Special.
Most all holster makers offer holsters for the Python.
Most concealed type holsters will be high-ride, FBI style holsters for these guns.
Check out holsters by Galco, Bianchi, El Paso Saddlery and other big makers.