Having owned 2 1980 elco's I know where your coming from. Off the top of my head I don't recall all the details. I guarantee that your question will be answered by the guys at elcaminocentral.com. I've seen the vin decoding listed on the site as well as people that could tell you any little thing that would indicate the model. Also, check to see if the engine is numbers-matching if your looking for something to restore. Otherwise just buy it and build it how you like :)
Hope I set you in the right direction..