Bulova under the 12, Self Winding under the hands, Swiss under the 6. No Serial number on the back of the watch, it just says Bulova Watch Co - Stainless Steel - Antimagnetic - Waterproof - Shock Resistant. Has a Speidel strap that looks fairly new.
the caseback is a screw on, 6 "teeth" for the tool to open it. When you say Datecode is under the serial number im not sure what you mean, there are no numbers or symbols on the back of the watch ( i have not opened it I am scared there is a gasket or something I may damage). What year was the watch you have produced if you dont mind me asking?
The Dial texture is a Sunburst finish.
The Watch cannot be accurately identified by Dial alone, Movement and Case type is also a factor.
Knowing the Year of manufacture (by using the datecode) helps narrow the possibilities.
Take a look at the Case of this circular 1950 'Duo - Wind' from the Database.
http://www.mybulova.com/watches/1950-Duo-Wind-345
here are some much larger pics and some of the back