TC Yeo, a local fan of Japanese watches sent me photos of his vintage Citizen Auto Dater.
I’m not sure where he bought the watch but Citizen was pretty active in Singapore during the 60’s. I believe this Auto Dater dates back to the 60’s as well.
The shape of this watch reminds me of the discontinued rectangular Seiko SARA from the Mechanical line. Here’s a picture of the SARA013.
Yeoman's Weblog 
That looks very nice. Any idea of how much it retails? I’m sort of in the market for a good dress watch now. Although I must admit, I like the looks of the Seiko SARA better – but I know they will be very difficult to find.
I’m not sure what’s the value of the Auto Dater. It is not something that is readily available.
I believe you can still get the SARA from Japanese online sellers or try checking with Big Time.