This is old news, MERLIN, Management of Equipment Resources, Liabilities and Information Network, was replaced by JAMES, Joint Asset Management and Engineering Solutions, in 2005! Information is still available through FIO requests.
One of my neighbours works at the UK H.Q. for JAMES in Warminster and has provided me with the history of my Leyland Daf and also the Radio Repair body that is fitted to it. This was a personal favour to me, so please don't ask me him to do this for you, please use the FOI option.