Ossia up?

[Fairchild]

The ly file below creates a single bar (ossia) below the main staff line.  How to position it above?

                       - Bruce

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\version "2.4.6"
                        \score {
                \relative c'' {
| e1   
<< { d } \context Ossia { b } >>
| e
                } %end relative
                \layout {
linewidth = 2.50\in
        \context { \Score
\consists Span_bar_engraver
\remove   System_start_delimiter_engraver
\accepts  "Ossia" }
        \context { \Staff
\name     "Ossia"
\remove   "Clef_engraver"
\remove   "Time_signature_engraver"
\remove   "Key_engraver" }
                } %end layout
                        } %end score
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%