This comes from the Buick ElCamino Post. Didn't Cadillac make a sort of Cruck back in the 60's? I can't remember the name of them & what years they were made. I haven't seen one in years.

I work in the oil business & remember a story about an oil company owner that would buy all of his field hands these cars because they were very reliable & tough, and they needed those qualities for all of the desolate areas they had to go to check on the producing wells.

If you read the El Camino history story (http://elcaminocentral.com/modules.php?name=NukeWrap&page=articles/hist/hist.html&height=4300&width=100%) you'll see the Cadillac first used the name although it was a 2 door coupe. Any Caddy/El Camino's that were made were done by either the owner or by a coach builder like S & S as funeral flower cars and such. None were released by GM. Here are some really good pages featuring Caddy pickups and other Caddy oddities.
1959 Caddy pickups and oddities. (http://www.car-nection.com/yann/Dbas_txt/Drm59.htm)
70-74 Caddy pickups and oddities. (http://www.car-nection.com/yann/Dbas_txt/Drm70-74.htm)
77-79 Caddy pickups and oddities. (http://www.car-nection.com/yann/Dbas_txt/Drm77-79.htm)