Neck edge revisited

I've finished knitting up all the pieces and put them together to start blocking, however this is when I noticed that neither my right or left front neck edge is long enough when I attach it to the back piece. I ripped back to where I started binding off on the neck edge and now it's too long. Sigh. This neck edge is giving me such grief. How is everyone doing the neck edge and arm decreases? When you get to the last few stitches you can't decrease both at the same time anymore so do you only decrease once? Any suggestions?

lisa