Muffler (far left), sleeve, and 4-into-1 header
Overview from 4-in-1 header
Muffler (the cracking is happening just at the mount point under the foot peg)
Outside crack
Cracks on the side of the pipe closest to the bike (peg is in the "up" position, bike is to the top of the picture).
Close up shot of the muffler innards.