This is a beautiful and interesting discussion--- highly informative for a 'jet-age guy'
Historical fact...the Douglas DC-6B was the absolute least expensive 4-engine piston aircraft to operate (per revenue seat/mile) because of its very reliable Pratt&Whitney R-2800CB16 engines.
And yes, I have about 1000 hours in the 'ole girl...a superb airplane to fly.
No hydraulic boost on any control surface, spring/balance tabs only.
Ahhhh, the good 'ole days.
