Looks like all you need to do is select the left edges of the 'extra' faces on the right, the ones you marked with a white border. Select only the edges that connect it to the 'main' layout (so in the case of the lower right bit, you should end up with 4 selected edges).
With the edges selected, click the 'Separate UV's along the selected edges' button. Go into UV mode -> Select an outer UV -> CTRL + RMB -> to shell. You should be able to move it around now. Place it on the other side, where it should fit in decently. Select the edges on the right side of your shell and press the 'move and sew' button or the 'Sew' button left of it.
Should give you a more of less symmetrical layout. Does that answer your question?