Been looking on the Franco-Prussian war blog at Franc-Tireur pics. Why? Well I am thinking Franc-tireurs would make an excellent F-P war reenactment unit. Ideal for woodland skirmishes, anyway. I don't suppose the German reenactors would be happy with that but as a persona that would allow for a certain personal input it could be fun.
You can download this 1901 book for free
Souvenirs d'un franc-tireur en 1870-1871: simple contribution à l'histoire des corps francs pendant la guerre franco-allemande
On the Miniatures Page there is a topic Franc-tireurs in the F-P war from where I got this image from.