I had an Elco just before the GN. I put an '80 Grand Am front clip on it and swapped the dash to Pontiac too. Had some Rally IIs on it, it looked so genuine. I caught people writing the VIN down in a parking lot once, obviously trying to see if it was legit.
I think I talked to this guy before at the Nats. it seemed pretty legit- elco with a Regal or actual GN front clip, and all the Buick goodies, if I recall correctly