Commonwealth half penny.

[Gaz T]

Has anyone come across the half penny having six strings to the harp. 
I believe it should only have five, the strings are also very thick possibly a double strike but looking at the rest of the harp I’m not so sure. 

[Gaz T]

[absence of uniformity]

Marked by the red lines are areas of the sheild and harp that appear to be doubled.

Is this the cause of an apparent 6th string I'm not sure maybe?