Cheers Aristo - fiendishly good!
Cheers Ginge - thanks for the considerations. You are quite right about the lack of definition In the pick-up clue. (had been up all night....).
As for the “OTE” and “LU” sadly it was not a sophisticated homophone as you have credited it, merely a reference to earnings on the tube = LU = London Underground (these drivers are well known down here for their outrageous salaries...)