Mine is identical to yours. I have just fitted a set of Akah 2-piece mounts. They're marked "10" inside their base, which I presume means 3/8" dovetail. They have 3 advantages; one they have a windage adjustment in the rear ring. This means the scope reticle can be put in the centre by counting half the clicks back to centre, then any windage can be wound out from the mounts using a bore scope. Secondly, they give a quite practical view of the open sights. Third they also look good.

The scope is a German one but 25.4mm/ (1.0 imperial inch) tube. I just need a session at the range to fine tune the scope and then; look out rabbits. Whoever did the wood on yours did a very good job, BTW.