I recently acquired this stamp and my first guess is a #7 or #9, especially since I only paid a few bucks for it. It appears to be from a badly worn plate. Also, it looks to have the frame lines recut on the left and above "ONE CENT" but I see no evidence of recut or complete outer frame lines on the top. Unfortunately, too much of the bottom is trimmed to use that part to help ID this stamp.
