Guy I bought it from said the guy he bought it from was issued this watch in some special forces he was in, in the eighties.  It is green but I am not sure about the whole story.
Any Ideas?

Not sure about the special forces link I thought the only Seiko they had considered was a A639-5020. There is a test comparison floating around somewhere. Love the watch though. Not seen tat one before. If you have time could you send me three shots so I can add it to the library?

many thanks

Adam

I have one in a similar shape, upside down horseshoe.

Adam