But different elements of a party could prepare different versions of the party ballot. It appears that this is what happened in Pennsylvania, where there are no known records of votes cast for the two slates. What is shown on Dave's (and other) results, is the votes of the highest placed Breckinridge elector on the Reading slate (John Ahl), and the highest number of votes for a Douglas elector who was not on the Reading slate. The leading Democratic elector (and Douglas supporter), Joseph Laubach, had 194,834 votes vs. the 178,871 for the leading Breckinridge elector, and the 16,765 for the best non-Reading slate Douglas elector.
Ah, thanks. That clears it up.