Looks like you're off to a good start with the stencils 

Although i cant really spot it in the pics, any slight overspray can usually be taken off with a little bit of Novus2 on a cloth, i used it on my KISS cab and on the Stern Galaxy cab i painted, worked a treat 

Thanks mate!,
I masked up the bits i wanted to keep, in the overspray areas and cleaned the overspray with Shellite (I dont have any Novus)
Worked brilliant with a chux!