I believe the 4310 and 4311 had the woofers surface-mounted but all of the consumer versions were recessed into the baffle. My understanding of the later driver alignment was to cluster all the sources closer together for near-field monitor use. But it really wasn't that much of a difference and the true studio monitors were already in a tighter cluster. (???)

What I've not seen before—but have no reason to doubt the authenticity of—are the wooden grille pegs (split dowels, actually) on mine.

???