Certainly not a double rifle, but the epitome of the all weather shotgun was well illustrated in the Ruger Red Label "All Weather" stainless shotgun, in the "Dull Gray" finish.
I totally love mine (and it happens to be one of the best fitting factory scatter gun I own). It is absolutely ideal in the duck boats or goose marshes. The fact that all internals are stainless too, aside from the striker springs I would presume (?), and the synthetic stock, make it impervious to rain, snow, boating splashes, mudd, salt, etc.
A few pop up on Gun Brokers now and then, and interestingly, they are worth now around $2,500 used, which is twice what I paid for mine new in 2003 or 2004.
I would definitely see the value of a similar double rifle, especially in damp equatorial forests for Bongo, Forest Elephant, Forest Buffalo, Giant Forest Hog, etc.
I am not sure if the gray finish, on top of the stainless steel, was a nitride finish (like the Glock or Blaser finish), but mine has not rubbed away in 20 years.
To be fully logical, such a double would need to be 100% stainless: barrels, action, internals, etc. and be stocked in synthetic material. In a way, it would be the double rifle equivalent of the R8 Professional: an indestructible TOOL.
PS:
Ruger also made it in a bright polished finish, but brandishing that thing in sunny weather was like setting up a lighthouse to inform any flying creature in a 20 miles radius to steer clear away