Yep, a rear roller and pivot points definitely says "oilfield". Pieces of drill stem were stored on the overhead rack, and a long set of A-frames (gin poles) and a winch were used to pull a section of drill pipe off the rack, stand it up, and screw the pieces together as the hole got deeper. There are lots of them sitting around any area where oil drilling goes on- - - -usually beat up and worn out a lot worse that this one, though!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!