Al I got to disagree with you about not many Hot Rods or Choppers on the road, most hotrodders are in car club and most also have chopper bikes as well and rego their cars and bikes on classic rego which is cheaper and the road insurance is a lot cheaper but there are restrictions in when they can take them out (club runs or short distants for testing or taking them out for work to be done on them) I also know a few hotrodders who have full rego and use their hotrod as normal family cars, I have a few mates who have chopped Harley's as well chopped Triumph that have full rego as long as they past the safety inspection all is good.
As for your mate and his Ducati, if the bike didn't come out from the factory with indicators then no need to put them on as they don't have the wiring to install them, my Norton has full rego and has no indicators at all, there are different rules for older bikes and cars, any bike after 1985 must have lights on and 2 mirrors as well indicators, so my Norton runs no indicators has only one mirror on the right side and don't have to run with the head light on, I have never and I mean never had any problem with the Police while out and about on my old Norton, yes been pulled over many times for licence check or speeding fines.
These laws are AUS wide for older cars and bikes and road rules have changed for older cars and bike as they know some older bikes just don't have the charging system that will allow then to run lights all the time or to power the indicators and a lot of changes have been made for these road users.
I know a lot of mates who have hot rods and chopper bikes and a lot of bike mates running without indicators, with all these hot rods and classic car as well bikes that are being imported from the States, if the cars are over 20 years old then they don't need to be converted to right hand drive and one of the reasons we are seeing more old classic cars driving around with left hand drive on our roads with full rego.
Ashley