looks to be a single shot spur trigger pistol from the late 1800's - early 1900's. Hard to guess a maker since there were literally hundreds, but if you type that description into google images and scroll for a while you might find a match.
Brass frames were pretty standard on these, they were cheap (a few dollars) back then. slightly more expensive models might be nickle plated, and for a few dollars more you might get a steel frame. It's missing the left hand side plate which will also be brass and is probably not to far away, and the steel barrel might be close by as well...