yes blevins,rare, but not quite flippin - the 5-9 GMC's did have that 5 window configuration on larger trucks, it has the 'usual' big window opening with a couple blank panels inserted ... interesting configuration, but try to find replacement back glass
glass removed and just
a cab - note the middle glass is full height, not like the small window glass .... I've seen pics of a number of them, including one someone put on a 1/2T
Bill