In the early F4u's there was no floor in the cockpit, just foot troughs below and aft of the rudder pedals and a seat which is suspended from the radio shelf aft of the cockpit and in the rear fuselage. (1 major readson why pilots generally do not fair well when an f4u ditches and breaks apart... ie, pilot stays attached to the rear fuselage and gets smushed.)
Anyways, when the F4u-4 arrived, it was standard production with a cockpit floor. Seat remained attached the same though.
Will try to dig up some photos I have somewhere.