Fun times! 'course having double redundancy via a mirror CPU+ memory: would handle the {un-tracked-down) random bit-flip, I might imagine, but I like your approach ..where space/cost matters too, eh?

Visited Houston once, enroute to N'Orleans w/friend; got the mini-VIP attendant; sent friend off for the newbie-Tour (as her physics was ~normal USian.) Deja-vu on some hardware du jour: they used same exact square illum. swithches all over, as did Bevatron C.R. (begun in early '53!) Reliable those--it it ain't broke, keep Using it!

Bet few realize: recall that famous monster room with all the Stations, (full-of-men + One1111ONE O N E female mathematician). ...
There was a full-DUPLICATE ROOM below that one! (!!) Idea was, should a none-such local zap or whatever we can imagine: tHey'd race downstairs, where the SPARE (presumably with its own separate main-power feed as well? forgot to ask that) ... already hotted-up! Gather they never had-to use it--or we'd have heard all about it. But Imagine That! [in 2019 crap-dollars..]
(There was triple-redundancy w/'voting' for the absolutely critical matters, but believe we all knew that). Clever Lads, those.

It's a mad.. Mad.. MAD... mutifarious World ... with lots-too-many of 'US' than in 1969.
(Most troubling? ..since then: a %disturbing of the inmates: became The Eloi ... (and we all thought that was fiction. in ~1896.) Nothing can Surprise anymore.