One word, google. You have to see if any body changes were made and if there wasnt. Then youll be all set, if there was, research more.
There probably is going to be some minor mods because of the decade difference. But shouldn't be anything that bad.
Search Cadillac Eldorado Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Cadillac Eldorado Experts