Some fascinating stuff here. I hesitate to comment, because what I'm about to say is only tangentially related to the discussion.
Like Brusby said in his first post, if the print is the final product, then I prefer a richer print, with deeper blacks--even if it means that just a little of the shadow detail is sacrificed. Of course, really skilled printers--using various methods, it certainly isn't as if there's one "magic recipe" that fits every negative/every printer's skill set and desires for the final image--can extract as much of that detail as possible, and they know when to let it go on occasion.
But in his job, the print itself *wasn't* the final product--eventually, it was going to be reproduced in a magazine or catalog by the half-tone process.
And that process, because of the way it works, just totally destroys shadow detail--you're using larger, lower-resolution, more closely spaced black dots of ink to render those shadows. At some point, what shows detail on even a not-terribly-well-made print will just become a black splodge with no discernible textural/tonal information.
I've actually run into the same thing digitally when shooting for publication--it's more pronounced if the final, published image is black and white, particularly if it's going on newsprint rather than in a glossy magazine, but it also works with color to an extent. If I'm shooting for a newspaper--which has a pretty coarse line screen on top of things--I always boost the shadows and increase the contrast a bit there, using a tone curve. On screen, it will often look too grey and lacking in that "punch" that creates drama and a tonally strong print. (You also have to remember that to reproduce "white", the halftone process can only use a limited number of small dots to let the paper show through; you're not going to get much detail at all in the highlights either, you can forget Zone 8, practically, most of the time.) I really try to make sure that when the paper comes off the press, I don't have any areas of solid black because I've let the shadows get away from me--while trying also to keep the noise there under control.
Eventually, if you work for the same folks enough and study the final, published result, you can figure out what their particular printing setup will be able to render as visible detail and what's going to go away. While I'm sure Brusby's original prints were, from an aesthetic standpoint, probably perfectly acceptable (even if not quite up to master printer level), his boss knew that he was not only going to lose the shadow detail you could see under backlight, he was going to lose a lot more than that, too, when the photo went to press.
(That's one reason that photo books printed today look better, in general, than those printed 40 years ago: with computers, we can manipulate images so finely to suit our press setup that we're going to see a lot more of the detail, particularly shadow detail, that exists in the print--and even the negative, if a scan of it rather than a print is used to prepare the plates--but wasn't able to be satisfactorily translated from darkroom print to printed page before Photoshop.)