If I remember the cockpit layout (and it's been a very, very long time)
The controls are Landing Gear; Propellor pitch, Throttle, flaps. At least on a C-2.
C-2 used radials, so the supercharger was geared to the shaft; flight power was from the turbo, So, you could use a "set" throttle, and vary blade pitch Turboprops run better at a fixed throttle setting, too, so blade pitch is good management tool.
I wondered about how they triggered the drop. Problem being there's not a lot of good places on the yoke to put a thumb switch. So, it's probably a switch in the overhead.
Or not.