Right!
Land/ditch immediately!
Anyways no written document you will find about the 412 MGB run dry capability although my maintenance manager told me once he saw a run dry unofficial bench test in Agusta's plant in mid '80; they cranked up the MGB with the rotor installed at operative RPM for a wile, than untied the drain plug letting go all the oil down wile continuing cranking.
The MGB went off after 50 minutes after all the oil have been spilled away.
Consider it was an hangar testing on a inoperative fuselage without any air cooling and moderate blade pitch, he told me.
No infos about CBOX strength without oil inside it.
Cheers
maeroda