Just to add to this thread, here's a picture of my current office. Still flying scenics around Mount Maunganui, New Zealand. Is a 3b1 with a 435 lycoming non turbo.
Wouldn't that revert it back to a G-2A1?
Knew a guy...ag operator with a couple of D-1's who flew carnival tours in the off-season back in the early 1960's. Said they used to wind them up to 3500, then yank and push. By the time they got translational, the rpm had bled off to around 2900, enough to fly. I asked if their engines and trans's ever made it to overhaul? He just laughed. *Nothing* made it to overhaul back then. He said that when they got the G-2 they thought it had all the power in the world! Ahh, if they only knew what was coming in 1966...