For the Kodak Medalist, the rangefinder imagce is formed by two different prism systems. When you have one half of the image not in vertical alignent with the other half, you need to tilt the prims forward or backward to change the orientation of one image. If the whole system is off in comparison to the viewfinder image, you rotate the main imaging prism of the rangefinder.
If I am having the same optical issue on two different cameras, I start wondering if maybe it is an operator issue, not a camera issue? Sometimes rangefinder patches need to be vieiwed from one angle for proper imaging and if ou go off angle a bit things get sort of goofy. Maybe try moving your eye location in reference to the viewfinder and see if this changes anything? Or rotate the camera slightly? I have a mild astagmitism and can get funny effects as I rotate because the correction of the eyeglass lens is rotating slightly. And oftnetimes the viewing distances and such of the viewfidner and rangefinder image are slightly off so a variation like an eyeglass barrel rotation can affect each system differently and make a minor optical design flaw stand out? Just an idea.