Seiko case and number query

[Spruce]

Apologies if this has already been the subject of a thread but I looked and couldn’t find it.

I have a few vintage Seikos and have a query about the numbers on the caseback and the dial.

By way of example, I have a 7S26-0480. I know that the first four digits, 7S26, refer to the watch movement but I’m curious about the second four digits, in this case 0480.

Do they relate to the type of case or something else?

 

[X350 XJR]

Spruce

Do they relate to the type of case

Yes, since the 7S26 was used in a variety of watches it seems like the second set of numbers refers to the case style.

 

[Spruce]

X350 XJR

Yes, since the 7S26 was used in a variety of watches it seems like the second set of numbers refers to the case style.

That’s what I was hoping to hear, so many thanks.

My watch has a see through caseback and I’ve invested £6 in a used traditional caseback on eBay. At that price it’s not the end of the world if it doesn’t fit.

 

[reverbtime]

Last four digits are the case code. Of the three 7S26 versions, I'm a fan of the A variant (made from 1996 to Oct. 2006). It seems to run better than the B/C according to Seiko watchmaker Spencer Klein.

 

[ewand]

FWIW, there's an awesome site ostensibly dedicated to Seiko World Times, by @dapellegrini and it also has a neat case number decoder which provides links to part numbers etc - really, really handy - Vintage Seiko World Time - Decoding Seiko Part Numbers, Model and Serial No