Just a comment, but--- only some academic libraries use Dewey. Many academic libraries use the LC (Library of Congress) cataloging system, which is a totally different animal.
I've never visited the Princeton campus or its libraries, but it seems that
Princeton may have used the LC cataloging system since the mid-70's, and has been using it for at least some of its cataloging needs since the 30's.
Try doing a search for the sort of object you want in the
Princeton library catalog, and see what comes up. It's common for many academic libraries to have their collections split between multiple buildings, which may or may not be attached, or jumps through several physical locations through the course of time. Or you might find [this sort of reference material] in *this* building, but [this other sort of reference material] is in *that* building. If you're in a fictitious university, you can get away with anything you want; but if you're going to set it in famous institutions, like Princeton, or Oxford, or Cambridge, or Harvard, or Yale, or wherever--- people will say, "Ahhh!" when you've got your details mixed up.
So, for example, since you're using Chancellor Green as a library, I'm presuming that this is set in the distant past, since Chancellor Green hasn't been used as a library since Firestone was built in 1948. Nowadays, it's sort of a
coffeehouse/student center. So, if you're writing about Princeton in the 1920's, it might be worth dropping a note to their refdesk and ask, "Hey, what sort of classification system did your university use in this particular decade?" since I'm not seeing anything that explicitly says Princeton has ever used the Dewey Decimal System at all.