The mouse(digital) is better than digital keys because our hands movements are analog(natural).
Testing "Lunar lander" using a spinner(also digital) was good but you are right,
the flight throttle controller(analog potentiometer) movements are close to the arcade cabinet.
(it is a spring inside the original lander controller, sure you can remove if is more handy for you).
The starting topic was about analog throttle controller,
game playing with the proper controller change the game.
For DIY a Lunar Lander controller using on MAME is necessary:
-one potentiometer(5k 10k 50k 100k)
-analog/digital interface (like the A-PAC from Ultimarc)
-Lunar_Lander_-_1979_-_Atari.pdf (Maintenance and Service Manual)
or modding a PC flight controller(only one potentiometer is necessary)