Rabe in relation to Dr.Kenneth Warrell, of course he has not commented on thre interesting sources...
First the comments by Hans Pancherz, one of the Ju-390 pilots who flew long distance missions.
Second the interviews with Dr Wilhem Voss about a Ju-390 flight to Tokyo from Bodo Norway via the polar route on 28 March 1945, as interviewed by British journalist Tom Agoston.
Third previous corroboration of Voss by Reichs Armaments Minister Albert Speer in his autobiography "Inside the Third Reich"
Corroboration of Voss and Speer by the U-234's radioman Wolfgang Hirschfeld in his book, "Atlantik Farewell: Das Letzte U-boot" about the intention to fly some of U-234's more urgent cargo for Japan (by FW200).
Further corroboration from Junkers historian Horst Zoller in correspondence with me about Ju-290 flights that a newspaper article in Germany from 1950s identified flights to Manchuria by Ju-290s in Deutsch Luft Hansa markings and at least one BV222 mission to Sakhalin Island.
The three aicraft withdrawn from Luftwaffe service and converted for long range flights to Manchuria appear to have been:
Werke nr J900183, Ju290-A7 markings KR+LP
Werke nr J900182, Ju290-A9, markings KR+LM
Werke nr J900185, Ju290-A7 markings KR+LN
They were then recoded:
KR+LP as T9+WK (lost over Russia)
KR+LM as T9+UK
KR+LN as T9+VK
T9+VK became A3+BB
T9+UK became A3+AB (lost over Russia)
T9+VK/A3+BB was the last survivor. It was damaged in a hanger at Finsterwalde by Allied fighters whilst in civil markings sometime around Feb 1944. It was later scrapped in April 1944 at Travemunde.