Genuine/pattern wing difference

whats an easy way to tell if a wing is genuine or not?

been told there are the 4 audi rings logo stamped along the back of them?

also i seem to have one genuine and one repro wing, the small lip where it comes over the inner wing is different.  one is a neat rolled edge (good fitting wing) and one has a right angled edge 10mm long, which i assume is the pattern wing?

any help please

Yep vag stamp on back edge where door shuts