Thanks Pete. I was told the incident was around 1988 but there's evidence that it was earlier, possibly around 1982.
As for the damage, well the bonnet doesn't fit and is bent in 3 places, LH front wing, LH just inboard of head lamp, the area that stress cracks - I feel that this may make the bonnet scrap and the rear RH side of the top, I'll try to upload images. I had a measure up of the front hinge boxes and there is a little difference between the hinge boxes but hopefully no more than the factory, I have access to a straight chassis to check. It is pretty rust free but unfortunately there has been damage from storage to the drivers side door and there are a few minor dents here and there, but I think a dent guy could deal with most.
It would be a great basis for a concours standard rebuild, I did promise myself never again.