Im looking to purchase a bag on etsy (gray vintage gucci doctor bag) and the seller gave me a serial number that belongs to a separate listing on ebay-- same style bag but in navy, that I also just so happened already saw the listing and am to be waiting to hear back if either one are authentic....I'm a bit skeptical about the one on etsy because the seller messaged me the serial number, as I've been requesting for a picture of the number.....