Hi purchased a Mont Blanc meisterstuck ball point pen from an auction site. The pen arrived with an empty refill. When I took the pen to a Mont Blanc shop for refill replacement the salesman advised the refill felt tight to screw in. When they checked serial number they advised serial number is eight characters and not nine. They were unsure if pen was genuine and said I have to send it off. Is there anyway to determine authenticity without sending this as I’ll need to get back to the auction house if product is not genuine.