That's along the lines I'm thinking. Maybe not the Marlins. Already got a lot of levers. Sharps would be interesting, but like the Trapdoor, doesn't strike me as suitable for the environment. I'ma gonna guess Ruger No1 single shot. Hella strong action for the +P loads Josh'll mod in for us. The few rolling blocks that quickly come to mind aren't in .45-70. Would be cool, though.
I noticed the Ruger too. Guess I didn't think of that one. I was also weirded out, kept thinking that there would be more lever action ones with this detail. But I'm gambling on the Ruger or Sharps, as well. Unless they are putting more lever action. Can't think of what else could use it and be included..