Bonzaii, back when those were built the US standard for general aviation was mph. I seriously doubt any manuals were printed in knots. There were some versions built for the US Army, but I expect those (early fifties) were in mph as well. Some were shipped overseas, but what units those airspeed indicators / flight manuals were in is anybody's guess, that long ago. Of course, such manuals for more modern Super Cubbies are available, but those are all 150/160 hp. Hell, once you get some experience in the thing you won't need the airspeed indicator anymore anyway.
