I know you may not want to hear this but I think the answer is that there is probably little or no data that carried through to the paper. (That brings up another wild card here too; whatever paper he chose, like whatever film he used, would have had a personality that would have contributed to the look. The negative doesn't work in a vacume.)
Seriously, it is very possible that Hurrell was guessing as the book was being written, based on his experience, about what he probably-sorta-kinda-possibly-maybe used for that special shot of "X", on that special day years earlier.
I don't know if there were notes taken by Hurrell or not, but I do know that I don't keep any camera setting records and only very crude notes penned on the boxes of my materials on hand.
The practical question is probably not "is the book is a true historical record?" though, but instead "is the information contained a reasonable guide?"
The latter seems likely and given the current market availability of Super X, at best the book gives you a reference of the type of film he may have chosen, liked, or got paid to say he used. Given that uncertainty, it would seem the specific answer is purely academic in nature.
Also given the maliability of most any film's/paper's characteristics/responses though development and exposure and filters on the lighting and Filters on the camera and ... It gets to the point where what Hurrell actually used no longer matters.
Most masters, in any trade or craft, get to a point where they can make various tools do the same work.
this brinhs up. the point of goodrecord keepingwhichfew of us re very good atmaybe, the attached file can be of some help.