The Credor brand was created in 1974 but when initially launched it did not have the same branding that we have come to recognize today. When launched it was a collection of models and not a standalone brand, there was a different spelling and it was a number of years before the name Credor and the distinctive “mountain” logo were introduced.
In the early 1970’s Seiko produced a number of high end models that were fitted with precious metal cases and bracelets. Some models were just a solid gold version of the standard stainless steel models while others were uniquely designed. Some of these high end models appear in the standard Seiko Japanese domestic market (JDM) catalogs but many of them appear only in the Seiko Luxury catalogs. These catalogs showed models that were available only via select dealers in a similar way as the Master Shop models today.
According to the Credor history page the brand was first created in 1974. No specific date is provided for this, but it is likely this was towards the end of the year, as no references to Credor can be found in the 1974 Seiko JDM catalogs Volume 1 and 2 or the Volume 2 supplement. In these volumes the precious metal watches are grouped into the Special Watches section at the start of the catalog.
The first catalog reference to Credor can be found in the 1975 Volume 1 JDM catalog. The watches were included in the Special watches section that contained the models with precious metal cases. The watches were not separated into their own section but were identified with the Katakana text “クレドール” (Credor) and mixed in with other watches. Each of the watches feature the Seiko branding on the dials and it is only their catalog descriptions that have the Credor reference.
The first time Romaji branding text can be seen is in a dedicated 1975 catalog showing the collection of 70 models. The branding is listed as CRÊT D'OR which is the slightly abbreviated version of the French CRÊTE D'OR or literally in English “Golden Crest”. The models found in this dedicated Crêt D'or catalog are the same models found in the main JDM catalog in the Special Watches section.
The 1975 Volume 2 catalog also presents the Crêt D'or models but this time the section is labeled as both Special watch (特選腕時計) and Crêt D'or (クレドール). The labeling of the section to include the Crêt D'or name presumably emphasises the growing recognition and awareness of the branding.
The Crêt D'or models appear in the 1976 Volume 1 catalog and this time they have a dedicated クレドール branded section but there are only 8 watches, covering a wide range of different styles, presented across two pages. The Crêt D'or models do not appear at all in the 1977 Seiko JDM catalogs.
The Crêt D'or branding continues on and can be seen in dedicated catalogs up until the first half of 1978. The Crêt D'or brand is surrounded with an ornate pattern that differs between catalogs but contains a consistent design language.
In late 1978 the branding changes from Crêt D'or to Credor. This new brand text is prominently displayed at the top of each page throughout the dedicated catalog. This is also the first time that the Credor branding, instead of Seiko, appears on the watch face with a number of new models introduced. Many of the existing models continue to be branded with just Seiko on the dials.
The ornate pattern design surrounding the Credor brand continues to be seen on the 1978 and 1979 dedicated Credor catalogs.
The first occurrence of the modern Credor “mountain” logo is seen on the 1980 Credor catalog. Credor state that the logo is a stylised ideogram from the symbol for mountain 山 that is modified to include the mountains rising to meet three stars in the sky. The base of the logo is also extended to show stability and the smooth curves in the base representing the softness and richness of gold. The extension of the base and the placement of the stars form an equilateral triangle. This also logically fits with with the original Crête D'or “Golden Crest” name as the crest atop a mountain range.
The new logo is prominently displayed on the cover and at the top of every page in the 1980 catalog. By this time the majority of the models were branded as Credor on the dial, but there were still a small number of Seiko branded models, but none of the watches featured the new Credor logo.
It was not until a year later in the 1981 Volume 2 catalog that the first 4 watch models are shown with the Credor mountain logo on the dial. These were two sets of pair watches of similarly styled large and small models with the silver dialed KEL 130 and smaller KSR 090 and the golden dialled KEL 144 and smaller KSR 104.
Credor has obviously continued to grow within the Japanese market for many years and today is a very well recognised brand there, it is only recently that the Credor brand has been made officially available outside of Japan. As can be seen from its origins Credor has always encompassed the high end of the Seiko models incorporating precious metals then precious stones and high level craftsmanship with unique design styles. The brand has represented the highest end of their specialist products and this is still clearly on display today with models such as the Eichi II and Fugaku to name just a couple.
I have scanned a number of the different Credor catalogs as well as the Special watch / Credor sections from the relevant Seiko JDM catalogs. Below are links to the full Credor catalogs and the relevant Seiko catalog sections.