As others have said, I'd only let the seller know if I knew them, otherwise it's seller beware. It's tough but if the seller hasn't done their research and hasn't shown due diligence then it's not my job to do it for them. Also, I've had to source all of my books on British predecimal varieties from England (postage and the exchange rate don't help) and if any local sellers don't wish to go the same lengths then that's their problem. Also, anyone who signs up here and asks a question about any coins they have will always get an honest answer, usually within a day.