I would like to list this vintage Lacoste sweater but I am afraid of listing a fake. The alligator is blue and is sewn on the right at the hemline. I have read that the really older sweaters did in fact have blue alligators. The tag does have the diagonal grain to the fabric. The size is listed as M (medium), not with a number. It is a heavyweight fabric with quality stitching. Is it authentic? If it isn’t, can I list it just as a sweater and never use the name Lacoste? I am a long time reseller and have a 100% rating, this has me stumped.