Rare early version 1964 Grand Seiko 43999 cal 430 , 43999 case back , Taiyo symbol , shows a three-pointed star inside a triangle, which also called the Applique Dial (AD) symbol. It indicates that Seiko used an applique for the logo rather than printing it on the dial, a technique which wasn’t exclusive to Grand Seiko watches. Watch only in good condition w GS buckle n strap
https://thewatchbloke.co.uk/2015/12/29/grand-seiko-43999-calibre-430/
https://thespringbar.com/blogs/guides/grand-seiko-collectors-guide
http://vintageseikoblog.blogspot.com/2011/05/reflections-on-1964-cal-43043999-grand.html?m=1
https://thegrandseikoguy.com/2019/01/16/seiko-sales-january-1966/