Citizen moved from the Jet automatics, with their circular geared rotor, to the more usual swinging weight design in the mid-1960s. Although the first Jet automatics with no day or date complications were a reasonably slim design, the later models with date or day and date had to be housed in rather deep cases. This was also true of the very first swinging weight models, as used in the ‘UNI’ (2410) and ‘SM'(4600) auto-dater models. However, Citizen was able to produce slimmer watches with the advent in 1965 of their 52 family of movements.
The Crystal Seven range is probably the best known of the 52 movements, but there are a number of other models, and one rather scarce example is the ‘Super Flat’. The name reflects the slimmer case design facilitated by this movement – my example houses a 5203 movement, with 23 jewels. So far I have only seen a few examples, all with 23 jewels:
The main dial logo is printed rather than applied, and on one example I’ve seen the ‘Super Flat’ name was printed in blue. The applied ‘7’ logo is also found on the crystal seven – the ‘seven’ refers to watches with day and date complications and was first used on earlier Jet automatics. The crystal is plastic with a ‘cyclops’ lens over the date.
The back is what I call a transitional design marked with the older style model number – APSS 52703. I believe the ‘P’ references the plastic crystal – if this were a Crystal Seven the model number would be ACSS 52703:
The serial number gives a production date of July 1967. Inside is the 23 jewel movement, and as with many of Citizen’s 52xx and 72xx automatics the centre of the rotor is black:
Shots of the sides of the watch illustrate the slim design:
And here you can see this watch at the bottom of the stack, to show how it compares to earlier models:
The Super Flat is a relatively recent addition, so I now need to update the Movement Table and 52 Crystal 7/Seven Star Family Tree to include it.