I note some increasing concerns about the number of fake shirts appearing on ebay.
I could list numerous tell tales signs which would help prospective buyers but this in turn would also help the people who are making the fake shirts.
So my advice is simple, if a seller claims to have a confidential source at a club and refuses to reveal name etc. then stay well clear. A genuine seller will be forthcoming with details which can be verified.
and secondly, if the shirt seems to good to be true, then it usually is !!