Bulova M6

This watch was my dads. It says 30 jewels on the face, as well as selfwinding. The back says anti magnetic, shock resistant, waterproof, 10 KT R.G.P. bezel, ss back. Under the serial number is a small M6. And obviously this is not the original band.

I am looking to find out the name of this particular model. I believe the M6 represents 1966 but I'm not positive.