Wasn't Cooper a financial guy of some kind? Bean counter or something?
Land .. stash the 'chute, scatter some cash to indicate a failed escape ... the search is less intensive ... skip to the Bahama's.
I don't know that they ever identified the guy. I recall that there were a load of suspects and a couple of FBI guys were sure it was some fella that was caught for a 2nd highjacking but my personal take is that at night, at 10k feel jumping over a forest at 200 mph trying to carry a boatload of cash he probably didn't make it. It was a very diffcult jump in daylight.
Of course they'll never know for sure if this is the chute he used, odds are that it isn't but I can't think of a way that they'll be able to prove it one way or another.