I reassembled all the parts into the painted case, didn't fit the front panel as I'm still working on it. The areas where the aluminium panels come together were left unpainted for earth continuity. The cheap Pots I used in the trial build have been swapped out for some TKD 2CP-601, 10k, Dual Gang, Log Pots. This pair of Potentiometers, including suitable shaft extension kits, cost more than the crossover circuits, but as they are in the output signal path, I thought it worth the expense. I had considered ladder rail stepped attenuators, or measuring the settings used on the cheap Pots and replacing these with good quality fixed resistors. I figured that the steps in the attenuator would have been too big for accurate driver integration and fixed resistors wouldn’t allow any fine adjustment for things like different room acoustics, a change of interconnects or Amp, so the pots seemed the best compromise. 

The new Pots have made an improvement to the sound, if only slightly, they sound more mellow, the originals sound slightly sharp/grainy in comparison. The main difference is the channel matching which is a lot closer on the new ones. I measured to check and they are within a couple of percent compared to eight percent on the originals.

The next thing to try is a bit of op amp rolling.