Don't have any direct knowledge of that particular airplane, but.....back in the mid/late 70's in N.O. there was a '337' that was staked out on the West tie downs, really nice red, white, and black paint and door and footwell windows just like an O-2, canvas seats, overhead towelrack antenna and lots of smaller whip antennas,blade antennas, flat antennas, and no spinners on the props.

It was obvious that it was an O-2 in civilian clothes.
Occasionally a very base model 'hohum' paint color Plymouth or Chevrolet sedan would show up, the pilot and 'passengers' (all wearing Robert Hall type suits) would take long, flat, hard cases out of the trunk and load them into the airplane and one of the passengers drove away in the car so it didn't sit on the field. Then the 'crew' would file a flight plan from Lake Front airport to Lake Front airport. It would disappear sometimes for weeks and then it's back, at least once with odd small sheetmetal repairs and freshly daubed on touch\up paint. Since we were Robertson STOL, Ralph the owner tried to track down the owners to see if we could sell them a STOL mod, he found out it was registered to a 'United Amalgamated International Corp.' of Oompah, PA.' or some such phony baloney name so we figured it was a DEA airplane. Might be what you're seeing, some sort of 'SHHHHH, nothing to see, keep moving' deal-
