Metal Bell System Sign, Saul Bass Logo, Thoughts on Origin?

[segaloco]

I purchased the attached sign on eBay to hang in my workshop and was curious if anyone might have some thoughts on where this sign would've lived.  Probably not possible to track it to a specific building, of course, but maybe the size or other particulars give clues to whether it was, say, on the side of a building, mounted behind a secretary desk, etc.

Included is a typical G handset for scale.  It's about 18" in diameter.  On the back you can see that it is mounted to the board it is on via bolts originating in the sign.  I haven't tried to take the board off to inspect the mounting hardware further but I'd rather not unless there's something significant to be learned from that.

I have no idea if the board is its original mounting.  However, whoever mounted it did have an eye for detail in that the grain of the metal brushing is all aligned, and nothing about it seems amateur.  I assume it is bronze as it is both very heavy, has that tinge to it, and this article describes the logos being primary made in aluminum and bronze: https://archive.org/details/westernelectricmagazine_1981_03-04/page/16/mode/2up

I see there is a pinned topic on the earlier logo and it's proliferation throughout signage, is there any such history concerning this Saul Bass logo's use in Bell System signage and such?  Of all the signs, I find myself often curious what might have happened to the huuuuge light up blue ones from the major offices, if any of those have survived until the present day or if they're long gone.  I don't think I'd want one myself, again, see HUGE, but a video I saw recently around divestiture time of them prying one of those off of one of the big sky scrapers had me wondering where they might have wound up...