So much to summarize since I was last in the thread- and that wasn't long ago!
-Price is an object, but it's flexible, this is a tool for my job that gets hauled about more days of the month than not, as more than half of life is spent in the north bush. All I have to worry about in life is the wrath of the Mrs, and that's more to worry about than one might think.
-.303 is just swell, as is .308, and on up. I'd take a .30-30 over a .44 Mag, too.
-1899's suggestion of the VC 9.3x74R double is very interesting. Short, compact, quality double at a very reasonable price, and barely over my 18" goal for the respective chunks.
-I like a good Mauser (and even LE) as much as anyone, but your barrelled action section is still very long with a legal length barrel, I need a gun that fits unobtrusively in a compact flight bag, yet still offers meaningful horsepower.
-Stainless would be a big deal as aircraft up north are by no means consistently warm and dry.