Nelson Credenza  

Woof, my guess is...probably
The drawer part of the pictured unit is exactly like the Gunmetal finish unit my late friend had, and it about his most cherished item. Back in the '80's, you simply didn't have much opportunity to find this level of high quality office furniture, because offices were still using them!

Is that a built in telephone?!
Is that a built in telephone?!

Yes, I'm sure the phone was installed into the unit.
Herman Miller offered other office pieces with built-in phones.
I can't tell if the open sections part of the unit is part of the drawers section or not. I thought that the top and bottom were separate......but perhaps this was a grand and unusual option.
I've not seem a comprehensive catalog of this period Nelson's EOG, which I believe was from the later 1950's (although the "Herman Miller Office" lists the EOG existing from 1952-1978....I think new more Knoll-like pieces like the above was introduced around 1958 or 1959...or possible in the 1960's.
I had always attributed my friend's credenza as being a 1960's piece.

Yes, the phone had to be...
Yes, the phone had to be optional. Info on this series is lacking. Mistakenly implied height, when I meant shorter in length.
The timeline is good to know Barry. I was under the impression these came out in the late '60s The two sections, top being the slots, and bottom being drawers are one complete whole. The upper, slot, section has a vertical scrolling enclosure. Not sure, but I think the desk portion can be stored in the unit...but I'm likely mistaken.

I'm not totally sure, Woof, but it's
possible that it was a custom piece.
Remember, this was at the height of the big company commissions, and both Herman Miller and Knoll made modifications to their office furniture to fit into a really large space, and remember back in the late 1950's and early 1960's, cubicals and built-ins weren't as popular as they later became.
Assuming that the unit was one piece, at that double height, I'm quite sure there wasn't a matching unit that was less wide. But I'm sure that the bottom drawer unit came in two drawer, three drawer and the pictures four drawer width.