Today's pick is a gold plated stainless Seiko Sportmatic seahorse on a two tone Speidel stretch band. Being the Sportmatic was an entry level watch it would have been like a Toyota Corolla with leather seats and automatic transmission.
It was only made in '64. Seiko had discontinued the seahorse line, which was based on a Chronos so I surmize they had some parts left and used them on the Sportmatic until gone. It was the only screw back case for '64 for the Sportmatic. The rest for '64 were push on.
Now, the nicer Seiko's of that time that were gold plated had between 80 and 100 microns of 14k gold applied.
The Sportmatic had 20.
They stopped showing micron thickness in '64 and started using "14k" across the entire lineup. Some say cost savings by reducing the thickness resulted in not showing the number of microns anymore.
The nicer gold plated Seiko's had solid gold markers. The Sportmatic had gold plated. Hence no "star" symbol on the dial. No 8 side star indicating solid gold or 4 side star indicating a little nicer dial but the 4 star is on the case back.
It had a hidden crown at 3 o'clock instead of 4. A gentle sweeper hand was used with the (what I belive is a mondernized 820) 6201 movement but I've not removed the case back to see.
There were other versions such as a nicer dial, and a date window.
An example of the nicer dial and date window from an Etsy listing. Note the 4 side star. It
sold for $280.