Were these "mechanical" gyros somehow vastly superior to the various MEMS contraptions, even the expensive ones? From my experience, the latter ones would dead reckon you to the moon within seconds.
I think so, yeah. The space age made precision manufacturing relatively accessible. The U.S. military had a pretty insatiable appetite for these kinds of things for all sorts of stuff. submarines, torpedos, aircraft, drones, and on and on. https://en.wikipedia.org/wiki/Inertial_navigation_system
a quick search didn't find any hard numbers. but, yeah, I'd bet a few dollars they they were (are?) very good.
