Okay... so undo the bb form the NDS and then remove the plastic cup (i assume it a plastic one) err how hard would it be? The threat of outing you to RB'ers is a nasty one IMHO.
As an example i sold an old steel frame on ebay years ago -- some rust and some surface rust & rust inside but solid. 3 weeks later i get irate emails from the buyer and an ebay item not as described saying the frame is trash and so on and that evans had said it was unsafe. i agree to take it back. when he finally turns up (forgetting to bring the bb seatpost and stem that were bundled in with it for £20) he has stripped the paint off the frame (badly and with a belt sander!) and there was a small pinhole in the seat tube. I asked where the rest of the damage on it is and that was it.
Fair cop it was a hole there - previously covered by reasonably tidy paint and probably not helped by the paint removal method. he too also had the gall to ask to buy something else i was selling (oh no not having this repeated again!) and when he found out i'd be binning the frame he wanted to take it back!