I've just today learnt that the black coating is a sort of tar that they used to paint over the epoxy to add extra insullation from rust. Apparently fairly common. Taking the car on would eventually require removal of this black substance in order to re-touch the epoxy - apparently quite a pain in the arse job. But the steel underneath is most likely to be immaculate
I saw the car face to face last night. I must admit, it is a beauty. There are less than 10,000 miles on the clock, and secondary indicators support that - the leather on the driver's seat where he gets in isn't much worn, the gearstick isn't smooth or polished and the peddles likewise don't appear worn down.
The interior was pretty immaculate. No cracking or real strains. The panels all fit together well, and the glove box seams are perfect. Exterior-wise the bodywork was near immaculate also, with the exception of a 50-pence piece sized dent on the t-panel near the driver's door. The drivers door currently sags, but can obviously be easily fixed. The engine bay also looks good (from my limited knowledge) with very little grime or rust. I had a spin in it and the engines sounded good and the ride was very smooth. Craig radio/cassette still in place and original carpets barely look worn.
Overall, great car and apparently one of the best example all-originals in the UK at present