The question you asked in your OP was
The first questions pertain to WW2 fighter planes, regarding basically how much thrust, and how many pounds of thrust were produced per horsepower at takeoff-power, at climb-speeds, at cruise-speeds/altitudes, at maximum speed and so forth
That is what I have been addressing ie the relationship between horse power and thrust.
the issue seems to come down to different prop-diameter/blade-geometry, different gear-ratios and so forth like barit1 stated
These elements have nothing to do with the basic horse power/thrust relationship. They do have a role though in optimising the engine/propeller match.
The horse power produced by an engine is given by the formula,
brake horse power = brake mean effective pressure*engine displacement*RPM/792,000