I have another French double action on the way to me. This one is a big 12 gauge with junk barrels, (Crushed by the Muzzel) it has double under lugs with 3 bites and a third hidden fastener. When it arrives I will check the proof marks but it looks like this one will become either a .470 NE, .475 #2 NE or a 500 NE. Which way would you go and why?