[skymstr02]

Sorry, this is not for real.
I hung the tank and took the photo. That drop tank orginally was on a Grumman F7F Tigercat, and has a 150 gallon capacity. Drop tanks are available in different capacities.
The standard Skymaster wing will not take the pylon mount that you see in the photo. The O-2A wing is built differently internally than a civillian wing, and is not interchangable to a civillian fuselage. There is internal structure to accept the loads from the hard mounts. The pylons are rated for 350 lbs max load.
In the advent of an engine failure, the external loads must be jettisoned, and I don't beleive that the local authorities would be keen on a couple hundred gallons of av gas potentially falling into the neighborhoods surrounding many airports.