I was just going to post this. I have no doubt it was made for Brian Gay. I know of no other Bettinardi BB8 that was made with a notch in the topline other than those made for Brian.
That said, the seller sounds like a complete tool. I didn't know that Cameron had the market cornered on the flymilled face. Plus, I don't trust someone who is trying to sell a $2,000 putter and can't be bothered to capitalize words in his listing (I'm not kidding either).
I wonder how this person got his hands on the putter to begin with.