18 months later…
I now appear to have reliable Gas and Electric data from Octopus (they have eventually fitted a dual band meter system).
I’d really like to import the Gas data.
@TrystanLea, I realise Gas data is of no interest to you, but for the wider community could we update the script to do both?
The tricky bit is the fact the electricity-meter-points string is hardcoded 
The rest just works.