The inside surfaces of the top were pretty grim but a scrubbing brush to get right into the dimple effect surface and plenty of hot soapy water got most of it cleaned up. The areas where the fittings were fixed required WD40 to remove the stains – then washed off with soapy water.
Took me days of careful easing the bolts holding the fixings in place and plenty of WD40 to remove the fittings without shearing the well rusted bolts. The fittings themselves were not much better but a couple of hours with a wire brush has given them a nice shine.
I originally thought the top was made about 1978 based on the glass markings but i have read that the little safety catches on the windscreen clips were deleted around 1967 so about 10 years older than I first thought.
Next stage to fit new seals and then I can start painting.