I just read this advertisement on the Cordite.com website:
Magnum Actions Australia
Melbourne Victoria Australia
smurray@vtown.com.au

I sell new made 'Magnum Mauser Double Flat Bridge Actions' all calibres. These are exact reproductions of the classic Mauser Magnum and have been purchased by Holland & Holland and Purdey. Exporting to USA on regular basis.

Would anyone here know anything about them?

Thanks and good hunting!