Steve,
The 'spin' is a normal funtion. The orienting prism is on a rotating axis in the housing where your VF locks in- if you carefully turn the notched ring inside the housing (you can carefully use your thumbnail and avoid the glass), the prism spins around to reverse the image coming out of the port (this is for the short VF vs. long VF attachment). It may very well be that your prism is just in the middle of the range. If it is loose or broken, don't try it, but that is one possible (and simple) solution to your dilemma if you havent spun it all the way through the range...
Another possbile thing to look for is corrosion- over very long periods of time, the prism coatings can go black, and need to be resilvered. You'll need to seek a qualified tech for that- any well-equipped motion picture camera service center should be able to handle it. If you prefer, there are a few who specialize in Russian gear in the US...I wont advertise for them, but you can feel free to contact me off list if you need a recommendation.
Best of luck!
Todd Liebman, DP/Steadicam
16/35/HiDef
Los Angeles, CA
todd_liebman (at) yahoo (dot) com