The simulcast is clearly coming from the old WBCS digs at 330 Stuart Street; the EBS test that played on both stations Monday morning mentioned only WBCS, and the request line being given over the air is the old WBCS 800 number, ending in "-0969."
Still unclear is which frequency the merged country station will end up on when the simulcast breaks up on or around September 5, and which set of calls they'll use. (By the way, the top-hour ID is erroneously referring to "WKLB Framingham-Boston." The legal ID should be WKLB-"FM," since WKLB with no suffix is AM 1290 in Manchester, Kentucky.)