I am in possession of a percussion cap side by side shotgun and am trying to learn as much as I can about it. The sides of the hammer mechanism say "Parker", but I have been in contact with the Parker Gun Collectors website and they have informed me it does not appear to be a proper Parker. Also indicated that the proof markings on the barrel indicate it was manufactured in Birmingham, England. I know nothing of the history other than it came out of a farmhouse in southwestern Indiana.