"Since you are tossing out dates, Joel, I'm interested in the transition between citterns/English guitars and the guitars as we know them. I'm thinking it may have started around 1820 and became more complete within 15-20…"
Al, That's the kind of thing you can either add as a link in a thread (there's a way to upload files to a given thread, click on the paperclip icon), or something as generally useful as that we can put under resources. Elaine has been going through period songsters and has a list of over 1800 songs at this point from the time period. The list is growing. I would put your spreadsheet under documetation.
I find that the most useful thing about the Weidlich book is his index of Minstrel Songs and which instructor they are in. It would be great to have some resources like that here on the site.
I'm not a re-enactor (though I do have a suit of funny clothes in the closet) so I usually don't always have to limit myself to completely period-appropriate performances. When I am doing a historic perfromance I use the "period" instruments that I happen to play — wooden flute, Scottish smallpipes, fiddle and sing unaccompanied. I've never earned the trick of self-accompaniment with fiddle. It's all I can do to play in tune when I'm not singing.
I mostly do 1812 songs from the Canadian point of view. My repertoire comes from old manuscripts and early published sources and also includes songs of the time that survived to be collected as part of the folk tradition in Ontario. I've been accumulating this stuff since the early 80s. Canada was much less urban than the eastern US at that time so there weren't nearly as many printed broadsides produced up here. Your Library of Congress website has lots of American 1812 songs online. (I'm envious)
In a concert setting, I'll usually perform this stuff in a more "folksingerly" context, as music from the past that has survived into the present. I use non-period instruments like steel-string guitar, mandolin and concertina and arrange songs to suit my own tastes — which to most people's ears are probably pretty arcane.