However this Ricoh World Timer is very nice indeed.
Width without crown: 43 mm (one says 44 mm)
Lug to lug: 51 mm (one says 52 mm)
It has an internal and external bezel. Seems inspired by a lot of European watch designs from the time. Like a Super Compressor with GMT-bezel added.
Ricoh - best known for copiers, cameras etc. - started selling watches in 1962 when they acquired a smaller manufacturer Takano, founded in 1938. More facts here.
I found this interesting picture at a sellers forum. It reads "WARLD TIMER" on the back case. An original error or a copy gone wrong? Source.
UPDATE MAY 2015:
I have been following ads for Ricoh World Timers on eBay for the past year and have only seen a few specimens and some of them totally beaten up. But then a few months ago things changed drastically. Now eBay seems to be flooded with Ricoh World Timer's. And they are all in perfect condition. The sellers are very frank and promotes them as "refurbished" and with "repainted" dials. It smells fishy - but it's difficult to say what is going on...
One way to distinguish original dials from the new "repainted" is to look for the word Japan and a number. The new dials seems to be missing this detail. Furthermore "World Timer" on the new dials seems to be in a thinner font than the original: