RM-

I've taken scouting trips in the Sierras (thick timber, rocky/rough mountains) with my WR 16-bore which weighs in the 12lb neighborhood.
It never felt heavy.
Perhaps if I were chasing hounds it might have been different - but my sense says that I would notice the rifle less.
I never seem to feel the 10lb loaded weight of my .458 when hunting or scouting either.

Funny about the WR website 'build your rifle' utility.
I've gone through the pages there a few times myself.
Even went through the motions of looking at the possibilities of having a Top Lever Hammer rifle built in hotrod 16-bore before I'd gotten tipped to the opportunity to purchase the rifle I ended up with!!
Had done the same with Butch Searcy here in California, and there was a fair chance that I would have had Butch build me a boxlock 16-bore...

Full-deck flat and filed ribs are a wonderful thing.
I've seen some pretty luscious swamped ribs on WR rifles though (look at Cpt Curl's .303 double rifle for instance) and I'd be hard tempted to order such a glorious feature on any 'spoken' WR double rifle.

As things go though -- now that Jno Rigby's back in business

if I were going for a Brit-built rifle I'd just call one of the geeks at JR and have them set me up with 'The Goods'
That's especially true ever since I've heard that they're going to show a snap-action some time in the coming year or so.
That would definitely be the cat's ass for a 'salute' big-bore cartridge rifle build.

Cheers
Tinker