Righto.com has a rather delightful introduction to and teardown of a Globus INK – a Soviet-era mechanical navigation aid for spaceflight.
As the article points out it is – obviously – flawed in that it calculates from a set launch position against a fixed orbit with no scope for either inertial measurements or orbital transfers, and yet I can’t help but find the engineering skills used in both the design and the manufacture of a device like this amazing!
And, even better, he appears to have tracked down the particular mission this unit was built for!