l_biceps
r_biceps
There is actually a space to the right that has to be left empty(made black in the templates below)for the two biceps to look similar, and rotate the image while not selecting that part. You also don't have to make them into 4 parts, you can just keep it one and flip it horizontally. Here is the toribash stock template with the space on the right made black.
l_biceps
r_biceps
Hope I helped!