Well, it's tedious, but that IS how these things get done...and Keltner didn't have access to the Internet, spreadsheets, databases, enormous and over-priced price guides, or even a backspace key.
Two things I can recommend to speed things along:
1. Contact the people who have done anything remotely similar, especially more recently. If you find someone sympathetic, they might give you a copy of their list of books in, say, an Excel-ready form.
2. Once there's a plan of attack, a webpage with information gathered to date can encourage contributors.
Also remember that, no matter how "complete" the list, as our Mr. Boox points out, there's always going to be one more company that managed to squeeze out a small run of one issue of a title before going under. (And a lot of those books are great reads, as we've all discovered here.)
And hopefully you've learned the most important lesson in the world for lazy people: Never, ever, say "someone should do this," because that person is invariably going to be you...