Hello Pekka,
perhaps this photo will help.
In the rear the vinyl (MB-Tex) is wrapped around a curved flat aluminum bar (23) that has triangular shaped tabs (hooks) that go into slots in the lid (6) and then are bent to keep the fabric fixed flat to the lid. You can barely see these tabs inside the holes that Brad has marked in his photo. On the front the vinyl is wrapped around the lid and held in place by two chrome trim pieces (31) which in turn are fixed to the lid with clips (32).
Let us know whether this helps you getting your problem solved.
I believe that the aluminum bar is no longer available but some times one shows up on eBay. The chrome trim pieces are also NLA.
It may be cheaper to buy a complete used lid. See for example: eBay 150517019802