Hello to everyone here! I am keen on buying a pre-owned Omega Constellation (please see attached photos). I have sent many queries to the seller and what I have gathered is that there are no major dents or scratches, it has never been serviced, all part are original and there is no box or proof of purchase. It is being sold to me for $580. Based on your experience, would this be a good buy? Any input would be highly appreciated. Thanks!