Telka iii double exposure prevention mechanism

I'm restoring a Telka iii. Yesterday I took to to a friend's workshop so that he could re-chase a crossed thread in the top section but it came back with the winder mechanism in bits. I can't quite get it to go back together so I think there's a part missing. If anyone was able to help me to identify which part is missing is be very grateful.

All sorted. Found some pics here. Although it's worth noting that the slotted washer is installed the wrong way around in these pics. http://herlent.daniel.free.fr/reparation/telka_iii/index.html