CL203 seat stuck - will not tilt forward

[GORDANM]

My 2007 CL203 C-180 Coupe driver's seat is stuck in the driving position. I can only get it to tilt forward whilst pressing it hard from the top and puling the release latch at the same time. It is a three- door and the driver's side cannot be used to access the rear seats. So far I have found that the problem is most likely in the cables in the back of the seat - too tight or too loose. I have researched the issue and it looks like the cables need adjustment. However, whilst models like W203 and some others have octagonal bits in the middle of the cable which are used for adjustment (turning them clockwise and anticlockwise) I could not find anything like that on mine (image of the cables inside the seat attached). I believe that the cable in question is the one going through the middle, from the top right (where the latch is) to the bottom left (which is where, I believe) the seat is stuck). I have not removed the seat trim yet, not sure if that would help (if a cable-tensioning mechanism is there).
Question: does anyone know how (where) this cable tension is adjusted?

 

[jls_rap]

For the cable 180, where you pull to release the backrest, the piece 175 connects to 170, which likely means piece 175 is either broken or has come out of its place. Please check this. Attached is a photo.