Check your front coil mount (I'm pretty sure yours' has the two separate coils). They are pretty much guaranteed to break at some point, and when it does you will loose your main ground contact for most of the wiring harness.
edit: I just saw that this bike was only on the road for two years before being hidden away in storage?
Incredible! In that case, the mount is probably OK, but still take the precautions below.
You would do well to relocate this ground to something more permanant. I drilled a hole through the plate that holds all of the connectors, sanded off the paint, and bolted the ground wire there, with some dialectric grease.
You should also run a ground wire from this point, to a handy location on the forks, to allow a direct path for the headlight and instruments.