I have that one on my Winchester 1400cs. Stop pins on all mounts don't fit holes in the Hatsan?...
Here's the rings: http://doddsports.com/hawkedovetail1high2pc1extension.aspxHere's what they look like on my Edge .22 Vortex in Striker stock. Compared to yours, my scope would appear to be sitting almost 2 inches farther back than yours and only the one scope stop plate with raised lip facing forward, back side of the front scope ring butted against that raised lip and screws loctited in the front 2 holes which would solve your broken screw issue by not needing to do anything about it.
LoL...I didn't come up with the idea, another member did, but it works, it works very well and why I did it on all my Hatsans. None of my scopes have slid backwards in the dovetails. None of my scopes have slid backwards in those rings and none have broken off a stop plate screw and between Hatsan and Hatsan built Webleys, I own a LOT of Hatsans....lol