I had the opportunity to climb into the cockpit a P47-D about 4 years. I did not measure the panel, but I do recall it feeling very roomy. I'm not sure if these will be of any help to you, but I included the photos I snapped of the cockpit.



You can see that the outer frame of the rudder pedal mounts are just inboard of the instrument panel (like you described), but the pedals themselves are quite wide. You can also see that the wear marks on the floor are more towards the inner edge of the pedal, so, the seating position might not be as uncomfortable as you think.

Hope this helps ...