Yes, it is definately an "aftermarket" part. It was on the plane when I bought it last week, and has worked perfectly for the 2500 miles of flying I did to get it home. I had no reason to suspect that it would jam for a flight of 10 minutes. It was free during the walk around. Interestingly, neither high speed nor low speed flight would unstick it (I tried both). It happly came unstuck when I hit some turbulence during a turn, as I reversed course after checking the windsock.
It worked fine when I got back on the ground!
It will be removed today, and replaced with the customary red cover, which hopefully I will not forget to remove (again).