So, the NTP from yesterday was actually answered pretty quickly in the comments.
Tis indeed the wing from a Cessna O-2A/Model 337 Skymaster.
I’ll be honest, when I saw it, *I* was stumped until I saw the tailfin in another part of the maintenance area of the hangar. Most of the area was blocked off, so I couldn’t get a good look at the fuselage, so I couldn’t tell if it was an actual O-2A, or the civilian Model 337. But all references to CALFIRES says they flew surplus O-2As, so I’ll go with that.
Back in 1961, Cessna introduced the Model 336 Skymaster light twin. It’s unusual push/pull engine arrangement had the advantage that if one engine failed, there would be no adverse yaw characteristics, something that is especially critical in light twins, particularly at takeoff.
The Model 337 introduced some changes, particularly adding retractable landing gear to the aircraft, and an air scoop to increase cooling for the rear engine and soon replaced the 336 on the production line.
The US Air Force, looking to replace its obsolescent O-1E Bird Dog FACs in Vietnam, and while waiting for the “definitive” OV-10 to arrive, bought about 500 of a slightly modified version designated the O-2A. The primary differences from the civilian model included windows in the right hand door to increase visibility, hard points on the wings for marking rockets, and extra radios for the FAC mission.
Including the 336, the O-2A, and several other civil variants, almost 3000 Skymasters were built. They’re still a popular aircraft on the used market. Having said that, they’re notorious for poor performance with one engine out, having just enough power to get you to the scene of the accident.
As for the oddity, conversions of the 337 to various configurations is apparently quite popular. One popular conversion is providing a larger engine in either the front or rear, and removing the other engine for increased space.
The US Navy apparently still operates on modified O-2A as “the Pelican” in which the rear engine has been replaced with a more powerful motor, and the front engine replaced with a sensor pallet similar to that used on the MQ-1 Predator.
Per NPS, the advantage of this arrangement is it can be flown in airspace that would be restricted to unmanned aircraft. It seems that it is generally used for range clearance at the US Marines Weapons and Tactics Instructors course at MCAS Yuma, and as a surrogate for unmanned aircraft in support of the course.