To get the manafacturing details of your Land Rover contact the British Motor Industry Heritage Trust, Banbury Road, Gaydon, Warks. I think the number you need to ring is 01926 641188, which is archives. They should be able to tell you the date of manafacture, original colour, body type, engine type, the date it left the factory and who it went to initially. You will need to quote the chassis number. You can get previous owner info from DVLA, but I think you have to pay for the privilege. Try the DVLA website. As for the engine, may be more difficult it it's ex BL/Rover, given their demise, perhaps someone else knows? You'll need to quote the engine number. Hope some of this helps.
Regards
Paul