Not sure what went there. On my '68 280SE LHD, that driver's panel has a pocket and a hole for the hood latch release. The passenger side only has a pocket. See attached. Of course the interior went through a pretty big change from the early 220 and 250 SE cars and maybe different than my 280SE. My best guess would be an aftermarket speaker.
The door cards are available precut and if you can get them, I would use new. The only downside is that you will have to "fit" everything as mentioned in the other post. The doors cards are ground to a taper where they fit into the lower door chrome trim along the edges. If you do not taper the cards, they will not fit at all. Ask me how I know.......
BTW, that pocket has to be sewn by hand and is not part of a kit. Just another difficult part of renewing the interior.