For what it's worth, the Behlen power steering on your 450 is basically an add on, as is a Charlynn, and none of those add on power steering set-ups work quite as good as the power steering units on the later tractors that are an integral part of the hydraulic system. The add on units are still a whole bunch better than nothing.
I've got a Behlen unit on a 1950 H equipped with a loader. With the tractor setting still, and the engine idling, it is almost impossible to turn the steering wheel. Once the tractor is moving though, the steering becomes VERY easy.