Hi Dave,

I do not know that reference number, but the watch looks like a pretty decent restoration. If 11404 is the correct reference number it would be pre- 1973 ish. From the style of hands I would say mid sixties or newer.

If that is an aftermarket bracelet he did well. To me it looks like a proper SK that has been brushed. Originally it likely would have featured a polished and brushed finish.