Either caliber would make an excellent choice. My choice would be 45-70, but my reasons are purely nostalgiac(spell check). I have not shot a 450 Marlin, but everything I have seen and read make it a top notch performer. I would go with the 450 Marlin, because I reload. I believe there would be more bullets available.

I totally agree with you on the Winchester. If you really want to get rid of it, give me a call. I might posibly be able to suffer through ownership of such a piece. Tom.