Mirror Delete Plate Gasket?

Syleng1 said
Wouldn’t it just be a gasket for a regular mirror?

also, every car I stripped that was mirror delete just did not have the holes in the door at all. 40 years playing in this hobby and never came across a plate like that. Interesting. Show more pics please.
Syleng1

I was told an export cars (Finland) that had a left (I believe) front fender mirror, and had this type plate on the door.
2 3/4" long. # is 2860748
Thanks for responding.
20200720 MDP Nr..jpg