This is an original Waffen-SS double claw mount 98k sniper's rifle.
It has all of the appropriate markings.
See "The German Sniper 1914-1945" by Peter R. Senich.
In addition to the number "63" acceptance stamp on the telescopic mounts it has the SS marking SSZZA2(SS Zentral Zeugamt A2 on the left side of the receiver ring.
The icing on the cake of course is the capture papers with the serial # of the rifle noted.