How about a '50 Studeamino.
Ernie Bletcher of California put this one together.
A 2 dr. Studebaker Sedan with the trunk cut off and an El Camino box welded on.
http://www.angelfire.com/super/1950b...Studcamino.jpg
http://www.angelfire.com/super/1950b.../studemino.jpg

You could do the same by selecting the 4dr. car/sedan of year of the El Camino you want to build. Instant crewcab camino.