Argh! This has to be one of the nightmare moments of reborning, you buy kits, which, let's face it aren't cheap and you carefully store them only to go back to them and discover that the ink from the Certificate of Authenticity has transferred onto the kit.
Obviously this is not the end of the world and can be fixed, but it's time consuming and ever so slightly irritating to have to do it.
So there is a major lesson to be learned here. DO NOT store the C.O.A's in the same bag as your kit.
Either put the C.O.A into a bag of its own so that none of the print touches the kit pieces or else store it somewhere else entirely.