It looks like its been made with bondo!
I used to have to walk beneath the wing of a parked 720B (which is still flying for Honeywell as an engine test bed) to get to the crew bus, it was a well worn PA bird. Rivet city, not pretty up close!
Is that the one with the 5th engine mounted behind the cockpit?
http://images.google.com/images?svnum=10&hl=en&lr=&safe=off&q=honeywell+Boeing+720&btnG=Search