I agree with Tim 100% on the Buff Classic sling set up:
"If it's a 45-70 BC, you'll most likely want to use a traditional muzzleloader type leather sling that attaches to the barrel well above the forend, most either use a butt cuff type or a barrel band mounted front stud."
It's called a Buffalo "CLASSIC", so a classic ML sling set up is the best fit for it with a butt cuff and a simple loop arond the barrel, classic in every sense of the word, and a little fringe or long hanging laces on it would not hurt either and really enhance the classic look....<><....