Tom:  I seem to recall the Screw BU cheer evolving out of the Cornell
fans reaction to the "Go BU" cheer.  It seemed to start in the early
70's, I think.
 
I'm also guessing here, but could the Ref ... Sheep cheer be a variation
on the NY Rangers fans "hello" to Dennis Potvin - "Potvin Beats His Wife?"
That was a very common part of the repertoire of the Garden's Blue Seats
contingent.