I would probably do as suggested and redo the block before I quilted--but I have to say that I recently was the winner of the BOM in my quild and had always been hesitant to do the BOM as I didn't feel confident enough that anyone would want MY blocks--well, when I was putting the BOM together for a Christmas throw I realized one was done incorrectly and had about the same problem as your block--I left it to remind me that we all make mistakes and not to freak about those that I make!