Hey Ted, looks like plenty of wood there to create the English grip and splinter. If there is a gap between the barrels there are a couple ways to close it. If the wood is proud, which it looks to be then inlet the forend iron a bit deeper, (preferred) or get some walnut veneer,(thin, like paper) and build the barrel channels up. Heck, your going it to hunt with it, right? As to finish you could use Formby's Tung oil low gloss, it's really not pure Tung oil, but it is tough and looks like an oil finish even if it's mostly poly? Looking forward to seeing the result!