\version "2.19.52"

customClefStencil =
  #(ly:make-stencil
    `(path 0.2
	  `(rmoveto 0 0
	    rcurveto 0 0.75 1 0.75 1 0
	    rcurveto 0 -0.75 -1 -0.75 -1 0
	    rcurveto -1 0 -1 1.5 -0.5 1.5
	    rmoveto 0.5 -1.5
	    rcurveto -1 0 -1 -1.5 -0.5 -1.5
	    rmoveto 0.5 1.5
	    rmoveto 1 0
	    rcurveto 2.5 0 2.5 4 4 4
	    rmoveto -4 -4
	    rcurveto 2.5 0 2.5 -4 4 -4))
     (cons -0.5 1)
     (cons -3 5)
     )

#(display     `(path 0.2
	  `(rmoveto 0 0
	    rcurveto 0 0.75 1 0.75 1 0
	    rcurveto 0 -0.75 -1 -0.75 -1 0
	    rcurveto -1 0 -1 1.5 -0.5 1.5
	    rmoveto 0.5 -1.5
	    rcurveto -1 0 -1 -1.5 -0.5 -1.5
	    rmoveto 0.5 1.5
	    rmoveto 1 0
	    rcurveto 2.5 0 2.5 4 4 4
	    rmoveto -4 -4
	    rcurveto 2.5 0 2.5 -4 4 -4))
)

{
  \override Staff.Clef.stencil = \customClefStencil
  c'
}