I like this model and have found various on sale/been sold on eBay and TimeZone. However I'm bit confused about colors and dial.

Is it supposed to be white tachy ring, blue dial and white subdials or is the ring supposed to be off-white (cream color)? I also saw one without tachy ring or the ring is there but without any markings. It's supposed to be original. Is this another configuration or is something wrong?

Thanks in advance!