Am no expert but I do happen to have a Lyman catalogue here in front of me and on page 6 it lists the Series 36M-50 for Mannlicher-Schoenauer rifle models 1950 or later. Mounts on bolt release arm and pivots on the arms pivot so it clears the bolt and yes the one in your photo looks correct. The catalogue is #44 but I could not see a date in it. Hope that is of some help.