I bought this Date and Day "S" on eBay a few months ago. It came in the original box. I serviced the watch and now it is in almost mint condition. since the original band was a plain strap I chose to spice it up with a nice JB champion bracelet with a suede inlay. It has the "up down" day date configuration and is in an oval shaped case. There is one other D&D "S" on mybulova, also from 1969 but the listing says its in a round case (which I think is incorrect). The oval case is short and fat compared to a D&D "Q" which is tall and skinny.
Case Serial No.