After my accident, I have decided to donate the below silencer in the name of Triumph science.
Not looking so good after sliding 90 feet on asphalt, with me following not far behind, I have administered the appropriate degree of dissection for your inquiring minds. This is off of a 2007 standard R3 with 14K miles on it. This is the left side single silencer.
Very interesting. Since one can see the cut-away now, it would be rather pointless to try to modify them; with drilled holes and such towards the rear of the muffler.