Spent most of the afternoon out in Mudd Library, trying to find some hint of information about this clock. Almost nothing. It was not in Prospect when they did an inventory in 1929. (Which makes sense, given that the donor is class of '35.) I found a photograph from Princeton Alumni Weekly from 1969 that may be a clue. It's this bizarre fish-eye lens photo, but there's a grandfather clock (distorted) in the place where my clock currently is. It would seem like a reasonably good assumption that it's one and the same. So I think we can pin the donation date to somewhere between '35 and '69, probably closer to the latter. And the donor turns out to be the same guy who donated the tigers between Whig and Clio, of all things. And, incidentally, the reading room where I was doing this research. The librarian and I were amused.