I think the 16 mm scope ring base is roughly the standard weaver width. On places like the bay, if you search for 11 mm scope rings, or 3/8 11mm scope rings, or cz scope rings, a bunch of options should show up. This type of ring will fit on other euro rifles, such as the rib on Haenels that weren't necessarily intended for scopes.
I don't think standard modern rings would be considered proper on traditional rook rifle, but they just might get someone going with a scope for a minimal cost and effort. Based on the picture, I'd pick a ring set that didn't use the screw or other projection as a lug, preferring a flat base against the top of the rifle's dovetail. And, while I wouldn't assume it, chances are aluminum rings won't leave marks on the rifle. Only thoughts, based on that .445 top of the dovetail measurement.
