The cartridge used in the youtube video looks like the 11.15x58R, Austrian Werndl M77, which was also used in a Mannlicher straight pull rifle. It has a base similar to the Mauser base, but is larger in diameter. I believe 45-70 would not be appropriate( or even 45-90 for the length). It is possible for the Stiegele, but I still lean toward the Werder. BTY, the Werndel was loaded in the US for a while( I have some).
Mike