SD logo on the bobbins began to appear sometime in late 1989/early 1990, but it wasn't until 1991 or so that the logo became consistent in use across the production models.
If he means the baseplate, why isn't there a pic of it? The 59 doesn't normally come with a logo on the top. It also isn't generally 4 conductor, but is a braided shield (unless ordered 4 conductor). I'd be concerned.