The Krigsspil site has a large number of downloadable flag images for the American Revolution. The flags are all in .jpg format, so they can be resized to fit whatever figures you use.
I’ve always wanted to do a Romans in Britain scenario. In recent months, I’ve been picking up Romans on Ebay as I’ve found them, and soon will begin looking for Celts and Gauls.
This paper model of a section of Hadrian’s Wall might come in handy. In the scale it’s in, you’d need 79 for a Roman Mile. The model is in black and white, but a little work with watercolor and a fat brush would quickly solve that
I don’t like Pringles chips. As far as I am concerned, they taste like cardboard. But the cans are massively useful for miniature wargaming purposes. Here’s a link to s a site that tells you how to turn those tubes into storage containers for your miniature wargaming terrain.