Gentlemen, I have no affiliation with this site, but I thought it is so good that it is worth sharing with everyone. It's site dedicated to vintage Citizen watches, and has posts on how to spot fake bullhead dials, dating watches etc. It's well worth a visit...

For sale Citizen diver 100m, case 61-5773, cal 5207, 23 Jewel, Parawater (Japan domestic market).. All original, dial+hands in beauty condition, some scratch on insert.. Bezel rotates freely, movement running normally.. Put this beauty into your treasure box for US$325, include PayPal fees...