Good heavens, what a project! I read your messages on the thread you put up on tune coding. My favorite system of finding out if something is related is to look it up on your site! Your Scarce Song pages are incredible. You've done all the hard work and I get all the fun! Seriously, I will most certainly check out the program. And I'll look up Simpson et. al as well!
I used Steve's index all the time. It's amazing. As it's in database form it's incredibly easy to search. The bibliography is a great resource in itself.
I find I'd like to broaden my knowledge of broadside printers though. I'm looking for something about broadside printers that would give me an idea of when they printed - which would be invaluable for the Bodleian too. I suppose for some there is no way of knowing. Is there such a reference? Do you have any recomendations?