For all intents and purposes, my MB-6582 is complete.
I have used PSU option A.
The PSU itself works properly, everything measures normal.
But...
I have this huge hum on the audio lines.
It gets worse when I connect the fan and is really loud when I use the feedback pots.
I've tried mix/matching the two c64 psu's I have. eg: breadboarded to use the AC and DC supply from each and the noise remains.
Even used a separate regulated 5v supply.
The only thing different in the PSU