I did something similar last year with a monitor without built-in KVM but with good DCC support (Ultrasharp U3417W) and Synergy [0].
I use Synergy as part of my desk setup already, but needed a way to view the UI of a normally headless machine. The solution I built was a small shell script that terminated the active Synergy session and started a new one with a different config file (so keyboard/mouse input would map to the normally-headless machine), and fired off a DCC command to the monitor to change its input. The same script ran with a different argument would switch back to the normal display/control configuration. This solution worked pretty well until I was able to retire the headless machine early this year.
This [0] is pretty close. IBM made a version of the Model M with Trackpoint but those are rare. Lenovo also sells [1] a keyboard that's basically a Thinkpad keyboard with trackpoint in a separate chassis.
The Webb telescope is a _wildly_ different apparatus, designed from the ground up to run as cool as possible, and with an effectively unlimited budget. It lives in the shadow of the Earth behind multiple layers of shielding. These "data centers" need to live in direct sunlight and operate as cheaply as possible _at scale._ Very little of Webb's tech is applicable.