WWG has a .457 Magnum which is esentially an elongated .45-70.
Marlin announced they would chamber for the .475 Linebaugh, which would allow its short cousin, the .480 Ruger to also be used.
Unfortunately no one at Marlin looked at the pressure specs for the .475 Linebaugh first, as some loads apparently went to 65,000 PSI. In a Marlin? Just say "NO!"
When Ruger developed the .480 Ruger they went with stainless with very high tensile strength - much higher than the normal stainless used in firearms production. Marlin was faced with a problem - if they didn't visibly modify the receivers people might come to think of the .475 Linebaugh pressures as acceptable in other Marlin rifles. I think they rightly decided that was a liability issue they didn't need to risk exposing the company to.