What actually happened: termination of Lend/Lease was because it was an Act for the Defense of US, which by 9/45 had been defended. The world was littered with US kit. C-54s were wanted by USAAF, not much else, so they set up as is, where is disposal auctions. Most went to the highest-bidding scrappie because they were offered with no documentation - to prevent uncontrolled arms trading. (In the Philippines the Jeep was esteemed, so to this day the urban taxi is the jeepney, rebuilt just as lovingly as Spitfires). Nearly-free C-45s were mildly helpful - UK had its Ansons and Oxfords, Canada its Cranes, France had comparables. C-46 was unloved by the civilised community.
And then there was the C-47.
What US could have done was same - auction for scrap. But they knew what that clever Scotsman, Mr Douglas, had created, so set up Depots all over the world, offering as is, where is, $50,000 with pedigree documentation: flat rate price, choose the ones you want and twist our arm for a pile of spares.
The A to the Q is that if US had scrapped or extradited all C-47s...life on earth today would be different and worse. The Dak ranks alongside the Hoover and Biro as key to civilised existence. Entire Nations could be managed from a central capital due to Dak. Am I right it is the sole type Declared by FAA to have no finite fatigue life? No DC-3 Replacement ever replaced - ask SAAF, operating them today. Some sales might have been won by SAAB Scandia, CASA Azor, HP Marathon, then Piston-Herald; Vickers might have actually sold some Vikings for money (most were Aid)...but...No. A civil C-117 Super-Dak would have been offered by Douglas, the Finance Industry finding ways to spread cost over a decade or so.
There would have been no missed opportunity to, for example, sell 672 new-builds to us. So important was it to the British Empire that, when we sent Keynes to negotiate out of the Lease-bit of Lend/Lease, we told him to come back with “an agreed number” of T-6s {US-built: Hood is right that more were under the different UK:Canada deals}, 18 transport B-24, 25 C-45F...and 672 C-47 (72/civil, 600/Empire military) H.D.Hall, Official History,N.American Supply, HMSO, 1955, P480; P.Butler,Air Arsenal N.A,Midland,2004,P39. For all this we "paid": a L/L Settlement net of Reverse was arrived at (after we had dredged records for spark plugs, £-sourced POL, victuals) of $650Mn. UK had received $27Bn., gross of $6Bn. Reverse. R.S.Sayers, Financial Policy, HMSO, 1956,P498/52. That was rolled into 15/7/46 $3.75Bn. Reconstruction Loan (extinguished in 2007).
All these financials were on the basis that "Govts. have taken full cognizance of the benefits already received (in) defeat of their common enemies (enduring value of) exchange of scientific and technical data could not be expressed in figures” Hall,P.480. So next time someone whitters about US theft of our Bomb, radar, all-flying tail, just dig out these numbers.