I unscrewed the back (3 screws) and took the rings off, the blades are now in the right position. put back together it seems to function ok. the diaphragm wide open is as you said, only 25mm. what is the shutter speed? I'm assuming there is only one shutter speed. why the high price?

http://www.ebay.com/itm/Mint-Wollens...-/160924061844