1967 JAGUAR 340 SCUTTLE VENT LID

[j.brown532996]

HI - Does anyone know the best way to free off a corroded hinge on the scuttle vent without dismantling the dashboard etc? My car has the lid shut tight and pressure on the lever under the dash moves it only very slightly - always under pressure to close. I have started a programme of dousing with WD40 wherever I can get the nozzle inserted but this is very mush done blind without seeing the hinges. I have dropped the Instrument panel on the dash and squirted in through the aperture into the area of the hinge.