I'm confused. I've got a 1391406. UK ISO, Greenock, 1996. It's fourth generation, according to Deskthority (no speaker grille, straight cable). According to Wikipedia, it should be grey label, but it's not, it's blue label. It's also got all-black legends, instead of the grey Alt and pale grey numpad navigation as seen above. (A month or two later I found another one identical to mine.)
It looks like things were not as straightforward as it seems!
PS weird USB extension lead …