For Treblinka II, for example, the aerial photos before liberation show hardly any buildings or signs of camp there at all.
The Exterminationist story says that all the traces had been destroyed to avoid detection.
If you remove that motive it seems rather odd for Germans to destroy all traces of transit camp that upwards of 800 000 people had been processed through.
The argument raised with regards transport manifest is hard to follow. Detailed transport manifests do exist for journeys to the camps.
I am not sure that this is actually true. At every trial a few typewritten documents have been produced that detail so many thousands of Jews transported. But these are hardly standard rail manifests.
Usually they look more like reports or purporting to be reports that are providing an SS office or Eichmann etc details of the "Evacuation" and how it is proceeding.
At least that is all I have ever seen.
Perhaps John could show us what he means by "transport manifests" and we could see if one should expect that details of the next trip the train took should be in the same file.