If the aircraft had the 'twist grip' throttle lever, with the button on the end, and large 'hand guard' disc, as shown in the pics of the FAA Museum example you posted elsewhere, then it would have the MkII GCGS (gyro) sight. These started to come into service with the RAF in Europe by late summer 1943, although not sure when the FAA got them for Corsairs. It's possible the Museum's example is a later, possibly post-war, aircraft, by which time virtually all fighters in British service had the gyro sight.
That resin sight in your pics is the correct type, but see if you can check period photos first, to see if the sight is visible. It's larger, more rectangular, and bulkier than the earlier MkIII reflector sight, and easily recognised, especially by the adjustment knob on the port side, and the curved crash pad over the wing span setting switch on the front (pilot's side).
Sorry I can't be definite, but I don't know enough about RN or any other naval aircraft.