Not wanting to p**s on your parade mate, just remember that with the roofing sheets YOU as the OWNER are RESPONSIBLE of the safe dismantling, removal AND DISPOSAL of the Asbestos cement sheets.
I am a building contractor that does get involved regularly with Asbestos removal, be very carefull mate !
I would suggest you get rid of the roof prior to selling, sounds daft I know, but it could cost you a lot of time, heartache and money otherwise.
PM me if you like and I can try to advise you, if you leave the sheets alone there is no problem, but if you take it apart you need to do it properly (getting a mate to do it etc) will cut no ice with the authorities.