The Ace weekend is completed with an interesting version, called the Discus. No doubt the fishy name celebrated Citizen’s ‘parawater’ (water resistance) system introduced in 1959 – Citizen was the first Japanese company to do this with the Deluxe Parawater. Like yesterday’s Ace, this has the 21 jewel movement inside but adds ‘Discus’ to the dial. Water resistance is prioritised as ‘Para Water’ is placed at the top of the dial, with ‘Citizen Ace’ relegated to the 6 o’clock position. ’21 Jewels’ printed in capitals is a nice variation. My example is from July 1961, and I managed to get a Discus hang-tag for this one:

The back on these is great, but is only lightly engraved, so many are pretty well worn smooth and illegible, except for the more deeply stamped serial number. By the way, ‘STAR’ is found on case backs through to the mid-1960s – it was the company/factory that made cases: