How to fit seat belts for 3rd seat in W124

Hi everyone,

I was fortunate to get my hands on a used 3rd seat for my old '90 300TE for less money than what the car once costed me. It isn't the right color, but I guess our kids only need a couple of months of soda drinking and icecream eating before that seat gets the colour of the 2nd row .

However, I'm stuck with a problem. I've got the seat in place alright, but there are a couple of arms fitted on the seat belts between the buckle and the fixed end and I can't figure out how they fit. I've fitted the seat belt rolls in place and figured out were the fixed belt end belongs, but these arms puzzle me. Can anyone provide me with a snapshot of a solution to this puzzle?

Regards, Jan