Certina Pointer Date - cal. 321

Hi all, I'm writing to all of you cause I find a vintage Swiss Made Certina with a pointer date complication, it is using a cal.321. I could not find a lot of information about the watch online, but doing some researches I've found out that the caliber is dated 1955 approx.

Can someone help me to recognize the watch or having further information about it? Thanks!