One of my sons has a Marlin lever action in .45/70 though I don't recall the model.
We had to take it back to the dealer when he first got it because it wouldn't feed. The gunsmith said he knew what was wrong with it. He must have because he fixed it. But it took a few days and involved driving back and forth to get it back to the store and pick it up.
My son attempted to put a scope on it and abandoned the project. It was too high, kept his cheek off the stock and because of the way he was holding it to see through the scope, he tended to get smacked with the scope.
It gets used as a brush gun. Say 50 yards or under. He's dropped several pigs with it. I don't think he's shot a deer, but I'm sure it would work just fine.