Tank leak at fuel indicator harness

Has anyone run into this before? I have an '82 Spectre that's being the problem child. I took the harness out and ran a bead of Permatex Motoseal where the fasteners sit (which is where it seemed the leak is coming from) and anywhere it seemed gas could escape. It didn't help and I am getting pretty disgusted.

Thoughts?

Thanks!

Did you replace the oval o-ring? They are still available. Also, do the fasteners have the correct washers? If they are like those on my KZ650-C1 petcock they should be a nylon type thing rather than steel. They also are still available. Ed

This isn't on the petcock - this is on the harness for the low-fuel indicator light. I replaced the o-ring, that didn't help. The nylon washers, I didn't bother because I figured they are just washers. So where it screws up into the tank, I ran a bead of Motoseal thinking it would get onto the threads and seal the threads and a bead around the fastener head between the washer and the screw head. No dice - it's still leaking past.

-Keith