One of interesting things about Seiko is, the more you've learned you'll realize that there are lot more you should learned.
|Stock photos from Seiko's website|
This SKX237 (green) is a part of series, SKX233 (beige dial), SKX235 (blue), SKXE07 (fluorescent/lume dial) and maybe one more with black dial, I don't know. Movement-case code is 7s26-6040.
|Left: SNK427 Center: SKX237 Right: SKX429|
Looks the same with 7s26-3060 (SKX425, SKX427, SKX429, SKX431) or 7s26-00d0 (SNK425, SNK427, SNK429, SNK431) but the diameter is slightly smaller, 34.2mm. Same lug width, 18mm and AFAIK only came with nylon/canvas strap with aluminum buckle, and you'll love this, drilled-lug on all side!
Well there is not much reference you can find on internet, maybe the series made for 'other planet' market :)