I'm just gonna throw it out there... have a look at your caster rod. youll notice it has thread on it.
that thread will adjust to like 3-3.5 degrees of caster, if thats not enough for you, then you should really be looking into a rose jointed type uber adjustable setup. as it is at this stage your going to need to flare or chop your front corner of your guard for this kind of alignment.