Here are some more photos of scope mounts on Mannlicher-Schoenauers:
An EAW side mount on a M1903 6.5x54M-S by G.Gibbs

http://www.eaw.de/assets/files/2014/EAW_Katalog_2014_Web.pdf
page 105
(Caution, for most Mannlicher-Schoenauers up to the 1950s you have to use the mount designated by EAW as for „Carl Gustav 1900”, that is small ring Mauser. The mount EAW calls “for Mannlicher-Schoenauer” has a flat-sided base designed for the late GK, MC and MCA models that already had a blind, flat plate attached to the left side of the receiver for attaching such a mount.)
Three more, top to bottom:
Vienna snap on, obsolete since WW2, once handmade one by one and offered by Steyr as a “factory” option.
Claw mount with front base dovetailed into receiver ring, frowned upon now by proof houses.
Claw mount with front base ring soldered on barrel shank