Thanks Spider.
My plan is to set the car up so its sat at ride height but without the offending wheel on.
Correct the camber whilst in situ on the car using the otherside as my guide - thats the easy bit.
Then remove the arm and bit by bit adjust the toe angle refitting after each tweak until satisfied using string alignment.
It doesnt have to be to the degree accurate.
Im sure there are quicker ways but after some time thinking it through - I feel this method suits me.