Interesting that you maintained the WWCR website, that is a 'cool' gig for sure.
I checked p.45 in WRTH and that is the first time I've seen a reference to a slice of broadcast band just under 7000 khz, but there it is. Would like to know where it starts and ends in khz and if anyone can find a reference to it in ITU or FCC documentation I would be interested to check it out.
Also, if the WWCR antennas in Tennessee point NE, then zl2taw's DX reception in Australia is either long path around the world off the front of the antenna or (hardly) short path off the back, either an impressive DX reception.