Looks like a typical Birmingham BLNE.

Probably made by someone like Midland or Harper, and marked "W. Jeffery". The name is not important, if in good condition with original chambers, it will be a nice, lightweight, durable gun, with appropriate loads. I shoots 2 1/2" RSTs in mine.

You may be able to determine the original proof date from the small crossed swords stamp on the barrel flats, if it is of the vintage that has them.