I would keep none of the Winchesters if I owned one good Marlin. Out of the 2 Marlins I would keep the 45/70 because brass.. parts ...dies.. load data..factory ammo is more readily available and it can do anything the 450 can do. All the calibers in the levers you mentioned are 200 yard guns so just put up with the 45/70- Out of the Model 70' s I would keep the 7 mag... I still to this day notice no difference in killing power between it and the 300 win mag...