hi bro
you can use the same jim lammers method again
make the pivot in the 0 x axis and duplicate it ,make it instance and scale -1 in x axis
lammer used 2 different mothods .. one was in 4.0 and the other one was in 4.5
you can use the 4.5 method
hope will help
Mr_Flamenco™( the Man Who Summoned By Mankind)