One document that has been used by revisionists is a document that doesn't say explicitly but implies that about 21,500 Jews in the camp are unable to work. However, I think there are some flaws with the way many revisionists, including intelligent ones like Mattogno, use it. Sergey Romanov has an article with the full correspondence in question:
https://holocaustcontroversies.blogspot ... r-and.html
One flaw that Sergey rightly points out is that this doesn't include Polish Jews. So we can't say that the 21,500 number is accurate since it definitely excludes Polish Jews able to work. However, I still think there is some kind of revisionist argument that can be made here, although this form of the argument would be much weaker and far from definitive.
It seems likely that Sell was fibbing on the numbers a bit in order to keep as many workers for himself. However, at the same time, he wanted to sell (no pun intended) a kind of plausible story to Maurer. If Maurer thought a little about it, then Sell would definitely get caught out, which he eventually did as seen by the last document. But Maurer seemed to hope that Maurer wouldn't think too hard about it and would just accept it without thinking much. The exclusion of the Polish Jews appears to be a cover that he would use if he did get caught out. But in order to sell this story as plausible, there would still need to be a significant number of Jews unable to work, just not as many as he said.
Now I fully admit this is not a completely fool proof case. It could be argued that he was counting on Maurer just accepting that he was excluding Polish Jews. This is possible but made less likely by the fact that he didn't explicitly say this, just said that Western Jews should be prioritized. That said, this isn't a completely terrible counter which is why I don't say that this is a completely definitive knock down argument. Nonetheless, I do think this document indicates a significant number of Jews unable to work. However, this should not be a standalone argument, but should be considered a weaker argument that should be combined with other stronger arguments.