the original wing beading has more of a shine to it,the copyed one's are duller, just need enough for one coner.
Brendan,
I have some wing beading here. Contrary to what you said, the stuff that I took off my own bug was certainly not genuine VW, and is shinier than the stuff I took off the '71 GAA bug, which I presume to be genuine VW. I can't see any other difference between them though, like the shape of the moulding etc. I can bring what I have to Limerick the next time I'm heading down and you can take your pick of the best of them...