I'm using the hardware PWM output on the Pi to generate the 'analogue' output. Without any filtering, I'm directly feeding it to the analogue meter. As it turns out: 50% dutycycle actually means 50% output on the meter scale :)
Lucky me, the theory seems to work....
My experience with the project has been very valuable. Interested in sharing it with https://medidordevelocidadtelmex.online/ team members so that they can also read it and implement something new.