Thats kinda interesting cause the '55 i have it was built in Sept '79 but its got the late model front end, dash, 4k motor and trimatic auto but the rest of its more or less ke30, except for the transmission mounts.
The typical aussie stuff (trimatic, BW diff, etc) were just to save on the import tax/tariff.
On the build plate at the bottom of it, it has "Plant/G.V.W" on mine it has the code "Z31". The code is where the car was manufactured, i've got the codes somewhere but i'm buggered if i can find it