If it's Ilmberger it will have a yellow label laminated into the inside surface showing the part number and the TuV approval. I've not seen any ID like that on Bestem, but I've only seen a few parts. Others I have no idea.
The BMW HP Carbon fiber will had the BMW logo, part number, year of production and motorcycle model all on the inside of the part layed into the resin....
All my parts have this except the rear hugger...
2012 BMW S1000RR - Motorsport - All Options - HP Carbon Fiber
2013 Kawasaki 300R - tastefully modding
2002 Kawasaki ZX7R - Race Bike, too many parts to list
2000 Kawasaki ZX7R - Sold
2000 Kawasaki ZX7R - Bone Stock - Sold