Conclusion:
On the same day as I got a letter in the mail from DL in Atlanta saying that they couldn't help, the miles showed up in my account. I'm not sure if KE or DL did the legwork (though I have a hunch), but I'm happy to have the MQM.
However....
They were not credited at 100% bonus as a GM, but only 25%. Not sure why this is, and maybe it's sacrilege on FT, but I'm not sure I have the patience to try to follow up with DL again. Can anyone confirm that they have received 100% bonus miles for flights on KE?
Thanks!