No I didn't turn my childhood 336 into a trapper carbine, but I came across an informative article that makes me want to consider finding a cheap used Marlin and making one. And of course there is always the chance of finding another good lever action chambered in .357 or .44 that already has a 16" factory barrel. All it would need would be a large loop and it would be RTG (Ready to Go, or as they say in Louisiana, Ready To Geaux.
There's also a fellow up in Alaska I think who makes, or at least used to make, modified take down 16" barrel versions of the Marlin 45-70 guide gun. Very nice weapons. I think they were called the Bush Pilot or something, made for bush pilots to take in their bail out bags.
Two very cool modified Marlins tells the story and has a couple of great pics, and once again it features very nice stock mount shell holders by this baldknobby leather that seems to be out of business.