Script Trouble and Edge selection

Hi i am using a scrip from Andrew Heumann to unroll an object i have modeled.

The trouble i am having is that i dont understand how the scrip is working. 

I need the scrip to unroll the object and allow me to select all of the 10 outside edges of the 8 faces which it is made from. This is for construction tabs.

Currently the object once unrolled only allows me to select me to select seven edges i need only 10the outer ones. 

I have attached the files below please recommend me some material to refer to in understanding scripting and a possible solution ton my problem.

Thankyou