Pretty it isn't !
Almost all of the standard Mission 765 crossover components were ditched in favour of new parts.
Out went the (high loss) standard electrolytics and in came the far more expensive polypropelyne caps. These offer [according to many] a much more open sound with increased precision.
To improve the power handling and linearity, the old ferrite cored inductors were replaced by custom wound air-cored inductors.
We then set upon a 2 week period of measuring and listening to optimise the crossover to the new bass units and of course the other upgrades.
Of course, the final tweaking of the crossover could only take place when the effect of the repositioned and optimised port were added. For details, follow this link