I didn't catch this before. I really need to go through these 1944 Soviet Treblinka reports again. They need a lot of proofreading, but have some interesting material.
The Extraordinary State Commission did an "investigation" of US and British citizens sent to Treblinka and killed. They wrote up a
Draft Report, which was totally swept under the rug.
They state van Eupen was commandant of the Treblinka death camp.
In June 1942, 3 kilometers southeast of the Treblinka railway station, 2 kilometers southwest of the village of Wólka Okrąglik in the Warsaw Voivodeship, the Germans built concentration camp No. 2, in which they killed civilians, mainly Jews, citizens of the United States of America, England and various occupied European countries – France, Czechoslovakia, Poland, Bulgaria and others.
...
This brutal extermination was carried out primarily by gassing in a specially equipped room.
Who do they say was in charge of this?
All atrocities at the Treblinka camp were carried out by the Germans under the direction and with the personal participation of the camp commandant, Baron van Eupen. (underlined with a red pencil in the original)
...
On the basis of the investigation carried out, the Extraordinary State Commission established that this monstrous crime – the extermination of US and British citizens – was committed by the commandant of the Treblinka camp, Baron van Eupen, the head of the camp, Oberscharführer Franz, his assistant, Oberscharführer Fles, Unterscharführers Fuchs, Mitzik, Stumpe, Schwartz, Zenf, Lanz, Hagen, on the orders of the Hitlerite government.
So the ChGK never mentions Stangl in any of their interviews or the draft report. Van Eupen gets quite a few more mentions throughout the various 1944 Soviet investigations than Stangl. Franz also gets numerous mentions.
If anyone is "confused" about the distinction between the Treblinka camps, they're in good company: the initial investigators and supposed eyewitnesses are the source of this confusion, both chronologically and geographically.
And to tie it back to the Ringelblum Archive, it's like the 1942 report got modified to become the Wiernik book, which was then clumsily stapled onto the Soviet Treblinka investigations.