Those fences are common on Evans guns and they have been seen on the guns of many other makers including Monk, Army Navy etc. Others like P Webley, W C Scott, Webley and Scott built most of the Evans guns. Those fences on guns built by Webley and Scott had a standard name, but I cannot recall it now. Bentley and Playfair and Hollis Bentley and Playfair built guns mostly for the trade like the above makers. They also produced this same fence and called it "leaf fence". The leaf fence cost up to an additional 7 bps per gun. Neat look.
