I certainly have.Wasn’t able to find a date but I haven’t seen a service panel like this before.
I wondered what the “hinges” were for when I took the cover off. Also wonder how the heck you were supposed to get access to the neutral bar as I didn’t look accessible!The Square D MultiBreaker line was Square D's first entry into the residential circuit breaker market in 1935. The breakers are factory installed to a internal tray that, when the cover is off the panel, is hinged to swing out and to one side of the panel. This permits routing all the neutrals along the back of the enclosure to a neutral bar mounted, not to the swing out tray, but to the main enclosure, actually BEHIND the breaker swing-out tray. The crazy thing, to me, is that one had to disconnect the feeder / service conductors from their lugs to swing out the tray to get at the neutral bar terminal screws. One is limited by the factory configurations of breakers.
I have, somewhere, a marketing advertisement showing a lady in full evening dress, resetting a breaker in a panel in the habitable portion of her house, with the caption to the effect that a breaker is simple, convenient and requires no parts to restore power in an overload outage.