I believe that the original MS records were destroyed in the bombing of the plant at Steyr in WWII.

However at least some of the stocks were made in Vienna... though perhaps only as special orders. I have a rather unique LH one for a 1903MS marked "Vienna."
Would anyone know where MS had their stocks built within Vienna, or any vendors there that might know?
I'm hoping to visit the city soon, and would enjoy getting a look at the location.