"If the original is destroyed, it no longer exists, so the 'copy' becomes the original :-) "

Well Mr Bush Lawyer,
shall I bring flowers or chocolates or flowers when I visit you in Jail? :-)

If you copy, then destroy by intent the original, you have destroyed by intent your right to lease.

If you copy then give away or sell the original, you have also forfeited your 'right to lease'.

If you have something in writing from the 'owners of the material for lease', you may have more 'rights' than the above.

If the material is now legally out of copyright under law, the situation may then be different. If, however, the material has been reissued at a later time than the copy you have by the 'rights owners', then you may still be in breach of copyright by 'copying'.