Thanks, Bob! I was on v1.50, but I just updated to 1.60 and confirmed (both via the game itself and via settings) that I was on 1.60.
However, when I connected as Disk Drive again and looked at the Data folder, I saw the aforementioned com.bwit.crossword folder and a user.xxxxx.com.bwit.crossword folder and when I moved the three puzzle folders (and their puzzle files) to that folder, I now see the puzzles! Yay!
Maybe there's something unusual about my PD setup, but all seems good! Thanks!