Ridge, do you have something portable AM that you can vary the size of the receiving antenna, or eliminate it easily? Something that would attenuate the received noise signal the farther you moved away form the source? This may get you closer to the problem line or insulator. It might speed up the power company if you could tell them which pole the noise is coming from. Just a thought.
Well, it's hard to say for sure, but it sounds like he's pretty much narrowed the source.
See if the power company is willing to send a truck out. The best thing is to be there when they arrive to show them what's happening. (They don't always announce themselves either so you need to be persistent in watching for them.)
As Ridge said before, it sounds like my power company in that they need a 3rd party to sign off on the RFI complaint before any work gets done -- so they can bill the appropriate party. This just adds a few weeks to the repair -- which will probably take less than 30 minutes.