Im trying to buy this vintage omega seamaster calendar automatic written 503 calibre, from a local individual. Please see attached photos. My thoughts *Its not in a good condition *The dial seem to have deteriorated *The second hand seems to be red according to https://omegaforums.net/threads/hel...seamaster-cal-503-with-red-second-hand.58802/ not characteristic of seamaster calendar. I have asked the person to share further pictures. asking price around 200$ how do I make sure this is authentic and how do I calculate its value? Please advise on this if I should buy or not. Also if anything specific to look for.