Got all the wiring done, crossover boards now have power to them and I have wired a couple of cheap volume pots into the output to control mid and tweeter levels. I didn't see the point in splashing out on expensive pots till I have an idea of how good the crossover is. Must say I am a bit concerned about all those wires and the possibility of crosstalk.
I managed to do a basic check that things are working. I played each pair of outputs in turn through a stereo amp and a pair of passive speakers. This confirmed HF/Mid/LF output from the boards and that the level pots were wired up correctly.
I now have to construct some new rear panels for my Yamaha speakers with three sets of speaker connectors, I want to keep the existing panels with the passive crossovers attached un-altered in case I ever want to revert to original spec.