Well having dug her out I have to say it wasn't half as bad as it could have been.
Bonnet, front wing, passenger door, roof, and rear wing all have fairly deep scratching from the roof sheets and need respraying. Most astonishing of all was the minimal damage caused by the joists, given that they free-fell 3-4 feet. One came down on the pillar just to the side of the rear window but only caused a small depression, the other which was two joists bolted together came down on the pillar between roof and passenger window but somehow has caused no damage at all ! Have to say I'm well impressed with how the bodywork stood up, you really wouldn't have believed it if you'd seen how bad it looked initially.
Anyway, together with other bits and pieces required like new seals for front & back windows and some repairs to scratches on the mirror housing I've been quoted £1200, which ain't bad considering. My excess is £450 and Direct Line estimate that the NCB loss will cost me £280 & £85 in the next two years, so it's definitely worth claiming.
As for the asbestos, my brother-in-law is a roofer so I let him sort it all out, he reckoned it was safe enough, what with everything being soaked with rain anyway which prevents any dust.