Looking through a group of pennies sent by a friend, I just noticed one has some interesting separation in the serifs.
It looks very much to be a doubled die, and this would be the earliest I have found in an Australian coin.

A few details:
very nice lower serif separation on the TT in BRITT, and look at the shape of the colons!

more doubled serifs and misshapen colons:

continuing to a lesser degree further around the legend:
