I can't find anything to link to, 'cept for other forums, but I live next to the Massachusetts State Police Academy and have heard that the Nazi uniforms were actually fashioned after the Mass State Police uniforms. IIRC the visiting Germans decided that style of uniform should be adopted because it looked intimidating and made the wearer appear something decidedly different than a civilian. Regardless, the police uniforms of the 1920's were perhaps made with equestrian and motorcycle uses in mind.