Here's my take on veroboard in a Teko B4 case. Not recommended if you're afraid of wiring,
but having a master plan with color coded connections is the way to go.
Otherwise I would strongly recommend getting the PCB from
@Aleph Null. But getting
stuff here in the EU from overseas has become a real PITA.
Anyway it worked straight away as intended. Trim pot set half way does the job.
(Sorry, no demo, because I just packed up my modular system again, but
@Aleph Null 's demo
is convincing enough).
The spray painting of the aluminum enclosure was the bigger obstacle.
Since I wasn't satisfied with the initial grey color, I tried to paint it over with a brighter tone.
But that resulted in blisters (as if you remove old paint with corresponding solvent).
Thus I had to sand it all down (grey dust everywhere) and start over with primer.