Dredging my memory banks, I attended school close to KLGA to get my A&P licenses. Lunch times, you could walk across highway bridge and get right on ramp in Marine Terminal area. Pan Am had the big seaplane hangar and a row of smaller hangars where Pan Am supported B-18, B-23 and DC-3 exec aircraft. Saw my first Dove there but it had fixed gear. Nose gear had a truly artistic fairing over it. A very pretty aircraft.
Going back to early post of flying in a Riley modded Heron, it was indeed Prinair operated. Good ride and those overhead escape hatches seemed like a good idea with all that water below enroute.