Wow, you serials people are the best!  I'm astonished by the plethora of
responses I received regarding a guide to the Early American newspapers.
And on a holiday weekend, no less.

The most promising lead are some guides from the Pennsylvania Newspaper
Project by Lydia Kellerman and colleagues.  In addition there are other
guides and a number of libraries with Internet-accessible catalogs that
include detailed holdings of items in the collection (a real boon to
problem-solving).

Many thanks to the amazing number of people who took the time to respond!

Crystal Graham
University of California, San Diego