Help identifying a similar sunroof "spring" part/replacement

I am looking for help to identify a similar part/replacement for this flat spring strip. It is a retrofit manual, thus the part is not in the ETK or any other parts catalogue that I can see.
The part is marked "F" in the image below, and is called a "spring" ("feder" in the German version). The large part (A) that it attaches to is the sunroof shade, and the "spring" is screwed on top of it (ie roof-side). It is a metal flat spring (likely made from spring steel) from what I can tell.

Here is another picture of it, in the flesh:

Thanks