I have some info on Citizen Crystal 7 to share today. This old Crystal 7 ad above suggests that the name “Crystal 7” came from the use of BK-7 crystal. Unlike Seiko 5 which was derived from 5 features of the watch, Crystal 7’s name came from its crystal.
However, there were some features that were used as selling points of the watch. They were:
1. Thinnest automatic day/date watch
2. Waterproof
3. Shockproof
4. Strong and clear crystal
5. Easy adjustment of day/date
Yeoman's Weblog 
Gold Citizen Crystal 7.
My friend from Brunei Darulsalam owned a piece of Gold Citizen Crystal 7. The watche is made of gold excepts for front glass and back cover. He is willing to sell. Interested buyeR can contact me at [email removed]
Sorry Jamal, this is not the place to sell watches. Please post a For Sale ad on the online watch forums. Remember to include pictures of your watch.