Injector 6 has gasoline residue around wiring.... what is this? It's visibly damp with the gas.

Only a couple ways gas could get on the outside of the injector. It's either leaking at the fuel rail connection or the crimped connection on the bottom of the hose where it connects to the injector body. Be hard for it to be a bad o-ring at the bottom or you would find the gas near the mounting plate on the intake.

Check your hoses carefully and replace the clamps on the fuel rail to be sure. I think you can still get replacement hoses from MSA for the injectors if it is the crimped end that is leaking. Not sure how they connect though.