For a big bore lever they don't get any nicer than the Marlin 450 MR, the MR is scarce with a 22" non ported barrel. They didn't make all that many and you very seldom see one for sale, when you do they usually go for 1k or more.
I like the 45-70 and I have a couple, but when push come to shove, I'd much rather have the 450 Marlin.
Put Talley bases and rings on it (with the rear base milled for their Peep Sight) along with a fixed 6x scope, and you'd have one heck of a rig (like mine)
I have a couple of their Scouts also but don't much care for the ported.
Phil
