BOLT was old Detroit Michigan callsign of the 927ARW that moved to MacDill some years back.. Kept the old Detroit callsign
Hard to keep up with KC-135's anymore.. They trade them around like baseball cards even more so with KC-46A's coming omline.
To muddy the 135 waters even more: When the 927th left Selfridge, the planes stayed, and were transferred to the MIANG's 127th Wing. (Along with some people who did not want to change drill locations, including a few in my squadron.)