As for finding a site for WMEX, are there any decommissioned former AM sites around Boston? I seem to recall one, on a dead end street somewhere in the 'burbs, but can't recall what station it was. 1570 Beverly, perhaps?
1570's tower was at Endicott College , and you are not going to get any sort of AM with more than a KW of power into a residential neighborhood in a suburb with enough money to tie you up in litigation forever.
They had enough trouble running flea power out of Endicott, the natives were not going to allow a huge antenna farm and transmitter there