VoltaBracket flipped vertically

[Daniel Rosen]

I'm trying to get VoltaBrackets to appear both above and below the Score. I've 
come up with the solution below, which works quite well, but I'd like to get 
the volta text to appear inside the bracket, as it does when VoltaBracket 
#'direction is not altered. Is there a way to do this? I can't seem to find a 
separate layout object for the volta text.

%%% example starts

\version "2.16.1"
<<
  \new Voice { \repeat unfold 12 { c' } }
  \new Dynamics \with {
    \consists "Volta_engraver"
    \override VoltaBracket #'direction = #-1
  } {
    \repeat volta 2 { s1 }
    \alternative { { s1 } { s1 } }
  }
>>

%%% example ends

DR