After between three and twenty-four years, depending on how you look at it, my big rack rig is now operational.
For a pic and the schematic, see here. The long version of the story is here.
I am indebted to Mike Hill of Mike Hill Services (MHS) in Milton Keynes UK for his help in sorting out what had defeated numerous others.
And at last I can get to play, gig and enjoy the folly to the full! Excited, me? Just a bit, yeah…