I'm surprised the patina came off so easily. I barely wiped it. It's tough because on one hand, I like the patina look, but it also looks dirty. I'm assuming the cleaned section is how it looked when it was originally in the hands of a cavalry soldier, so part of me likes the idea of it looking that way, but on the other hand, I can't really tell what's patina and what's just old dirt and grime that has no historical significance - like the old varnish and dirt layer on old paintings, it's not what it was intended to look like. But I agree, in hindsight I would've just left it alone, but for some reason I felt obligated to do something, considering it seemed so poorly mishandled and treated at the flea market when I found it.
I guess the plus side is I was so gentle with it that I'd be surprised if I removed any of the actual brass.