Stuart, I have one photo of a group of Prussians just after the 1864 war. They have some of their gear on.
I was just recently at the Bavarian Army Museum in Ingolstadt, and they had a superb exhibit on the 1866 war. The focus was on the engagements between Bavaria and Prussia.
I will try to post some photos when time permits. I would recommend viewing the exhibit on the museum website. They had lot of Bavarian field gear items, but most focused on 1866.