An open sighted lever action is kinda specialized.

Why no scope? I've hunted the Peninsula for about 20 years and I've never felt handicapped by carrying a scoped rifle. Unless you know for certain your shot is going to come at spittin' distance,I'd reconsider the scope. A 1-4 or 1-5 would be perfect. A low power scope has a large field of view and gathers more light than open sights. A scoped rifle is easier to shoot well also.

The .308 would be a great choice. With 180s it'll put the smack-down on any Black Bear you'll come across,it'll also reach further if you do run across a monster out across a clearcut.

A Remington Model 7600 would work nicely. Other than a semi-auto,nothing is faster than a pump,if you think you'll need a fast follow up shot.

Even if you have decided on a LA 45-70,I'd still consider a low power scope.