Omega Pie Pan 星座八卦面，烏蠅字
The Omega Constellation pie pan dial was so named because of its similarity to an up-turned pie pan. This is the one of the most desired Vintage Omega as its a constellation with the Pie Pan and big markers dial in gold cap version plus the Omega bracelet. In Asia its called the Pa Qua dial 八卦面，insect fly markers 烏蠅字, I don't have many vintage Omega but this will seat nicely with the rest.
According to Desmond, an expert in Omega, the Calibre 504 was the first date model to appear in the 500 series Constellation range, believed to have been released just after, or concurrently with, the calibre 502 non-chronometer date model. Only 25,000 calibre 504s were produced, adding to their collectibility, and, as such, the calibre often has a special place in the collections of Constellation aficionados. The date setting is not of the quick-set variety and it is quite a laborious task to set the date if you take the watch out for irregular walks on different days of the month. Coupled with its comparative rarity, it represents good historical and investment value. Calibre 504 featured a number of very attractive dials with arrow-head, faceted and onyx inlaid markers. The first dated version of the Grand Luxe was also powered by a calibre 504 and the gold dial with gold and onyx markers is a feast for the eyes.
Vintage Omega Constellation (Center & left with Pie Pan dials)
機械時代星座 Mechanical constellation
Cal. 354 - 1952年，官方的第一星座，17石，揰陀 First series, Bumper movement
Cal. 501 - 1955年，自動，早期19石，後期20石 Automatic (Often found in Seamaster)
Cal. 504 - 1957年，初見日曆，24石，呢隻罕見靚狀態 First with date (Chronometer grade Constellation)
Cal. 505 - 1957年，24石，取代 Cal. 501
Cal. 551 - 1958年
Cal. 561 - 1958年，最常見的機芯 Most common
Cal. 564 - 1965年，可快速調較日曆 Quick set date
Cal. 751 - 有星期，日曆，抗衡勞力士day-date，鮑魚殼 Day date