Williams and Powell of Liverpool sold a 12 G, hammer gun named the 'Simplex'. This gun was built to J. Williams patent #1247 of 1875. This patent included an extractor with twin external legs one each side of the barrel lumps.These legs slid in slots cut in the action bar; much the same as the Riley. Williams and Powell gun #7060 built to this patent was in my collection for many years.

Roy Hebbes