GCarlover, have you tried any props beside the 23" pitch rehubbed for a Johnson? What is the prop make and model that is pictured? Seems like an ideal prop for you would be a Raker 22". With a 140 HP Johnson, you should go about 57-58 MPH turning about 5,700 to 5,800 RPM's.
Yes, post some more pictures of your beautiful boat.