I have an autographed copy of Col. Gregory's book. I love the photo taken at Wright Field of him, Sikorsky and Orville Wright when the first R-4 was delivered there.
Not long ago, some of his desk models were being sold on eBay....but no early helicopters. They were in pretty rough shape so I passed.
I can't help on the CBI film, but there
was a TV movie in the 80s about female helicopter pilots/spies in Europe (no I'm not making this up). They flew modified Bell 47s with open cockpits (rather similar to the 47Bs and early H-13s where the top half of the bubble could be removed). It was extra cheesy....think Charley's Angels meets Airwolf.
IIRC, it was called the Whirlygirls or something.
In the 1950s, there was an anthology series on called
Flight...telling stories of pilots. Stories were introduced by Gen Kenney.
There is an episode on YouTube featuring the R-4 telling a story of a rescue mission in the CBI. The ac used for the ground shots looks real (I wonder what happened to it/) but had no window glass, all the flying shots were stock footage from period.
https://www.youtube.com/watch?v=I-6_DX6I_Jc