Aussie cars were different, the lucas parts are to do with legalities when they were built. A certain amount of parts had to be sourced locally. These were built from 53-56 here with some changes (like hanging brake and clutch pedals in 55 and a different front bar in 56, pretty sure they went to 12 volt +ve earth at some stage too.
In 57 they started building Chrysler royals off the same body with different front and rear panels, wrap around rear glass, different dash and a v8 option. They also extended the wheel base by mounting the diff further back on the springs by 1 inch.
Just a few things I learnt while researching my cars, I'm now building a chopped and 2 doored 58 Chrysler Royal AP2