Sorry Huvius, the bolt stop is the original one. That rifle is an early pre.WW1 and the modified release appeared latter.
All the parts bear the same serial number and the rifle is perfectly original, without any modifications from the day it leave the Oberndorf factory.
Notice also that making that kind of mount is not very difficult, a lot easier than doing a full handmade claw mount.
Will try to publish some pictures in the nearest future.
DORLEAC
www.dorleac-dorleac.com