TTN, contact the clearance department at Northolt. He may help or pass it on yo the Media guy at MoD.
Under the 30 year rule they may well be declassified. As they have probably not been published the Crown Copyright 120 year rule will then apply.
Enjoy.
PS,
Work cleared and I published 9 years ago has now been refused clearance after 're-editing. The information, now 40 years old is deemed too sensitive. In reality we think it is a young no nothing who finds kit easier to say no.