There is a 20 bore VH Parker with 2 sets of barrels for sale locally. Both sets are numbered to the gun however the second set is 30" marked Vickers and has a vent rib. Others are original Vulcan steel Grade-V 3^3 weight barrels on a 0 frame. Very high condition with most case still present. 1905 manufacture with capped pistol grip and a small repaired chip in the toe plate. Gun has been in the original family it's whole life but no-one seems to know about this second set of barrels. Anybody care to venture a guess?