It's going to be a Bubba'd rifle anyway so what you use as a wood finish won't matter. I'd suggest Pure Tung Oil instead of RLO or
BLO
. When properly rubbed in(one coat per day with 24 hours drying time between coats using a new lint free cloth every day.), it gives a hard, shiney(more of a sheen), waterproof finish that keeps everything else out.
Any stain
must go on before any oil, but especially Pure Tung Oil.
Make sure your smithy knows what he's doing when he installs the barrel. If he doesn't have the right tools, as in barrel vise and action wrench, it's easy to twist an Enfield receiver. And proper head space gauges can be rented for cheap. Don't let him buy 'em as you'll pay for 'em but won't get to keep 'em.