Full respect to Alan for undertaking this trip!
I don't know if he gets to read TM, but I would add the following to his preparation list:
Replace Banner battery if fitted.
Replace stock fuel pump with a superior item.
Reinforce fuel tank brackets & regularly check tank strap tensions during trip.
Familiarise yourself with the location of the fuel pump safety cut-off switch.
Consider fitting an off-road type rear tyre and use a 'slime' type puncture prevention product in the tyre.
Fit Blockley front tyres for more tread depth.
Consider replacing stock regulator with H-D one and solid-mount it to the bracket, eliminating potential rubber bobbin failure.
Take spare exhaust bobbins.
Fit high quality adjustable shock absorbers (and have them set 'soft')!
Remove NVH bevel box mounting hardware and replace with Phil Bleazey's solid mount kit.
Take a spare fuel filter.
