This is a big mistake on your part. Beckett has no way to know if the patch has been replaced. They do not have that expertise. They grade the cardboard, and the autograph, not the memorabilia. You say you need to side with the grading companies, however, they have not taken a side on this specific matter. No where on their slab does it indicate that the patch is original. At least you should state in your auction that the patch has been replaced or improved post production.
Once word of this gets out, and it will quickly, the collecting community will be more aware (this isn't the first incident of PWCC selling fake patches) that the patch fakers use PWCC as a shield. I have been battling patch fakers for close to 10 years. I have assembled databases of key cards and was even invited by Upper Deck to photograph every patch card that was inserted into 2008-09 The Cup, for this exact reason. I still have my original photolog of over 28,000 cards. They invited me to do this because they were aware of my fight against fake patches.
So you can imagine my disappointment with your position being that PWCC will hide behind Beckett and patch fakers will hide behind you. This is a terrible thing for the long-term health of our hobby and the values of the cards in people's collections.
I strongly urge you to reconsider your position and to realize that Beckett is not an authority on fake patches.
Regards,
Jeremy