This Suhl type scope mount certainly is not "Mauser factory original". Mauser always used their own rear ring design on a square bridge, with a sideways push-button release, when a scoped rifle was ordered. Such Suhl type mounts as on your rifle were usually put on by individual gunsmithes who retailed rifle and/or scope.
Until a few years ago the German proofhouses accepted most rifles with front scope bases dovetailed into the receiver ring,if the cut was not too deep. They simply pushed the base out of the dovetail and had a look. If the metal below the base was intact, the rifle was accepted for proof. If the barrel threads were visible or even cut into, the Action was rejected. But this was still the time when most rifles were for standard, not magnum, pressure loads, most Germans using factory loads only. The proofhouses now frown upon cut receiver rings, as more and more large base, high pressure Magnum cartridges are used and handloaders often try to squeeze the last few m/s or fps out of standard cases, making a 30-06 perform like a 300 Win Mag or a 7x64 like a 7mm Rem Mag.