Parenthesis problems

[Hilary Snaden]

Many thanks to the people who explained how to set the size of 
parentheses independently of the notes within them. Alas, this brings 
new problems, illustrated by this code snippet.

\score {
  \relative c'' {
    \clef treble
    \parenthesize ces \parenthesize c! \parenthesize cis s
    \override ParenthesesItem #'font-size = #5
    \teeny \parenthesize ces \parenthesize c! \parenthesize cis
  }
}

The second bar (the line starting \teeny) puts large, clear parentheses 
around small notes, but the opening parenthesis collides with the notes' 
accidentals.

Is it possible to build up the required [large open parenthesis + small 
accidental + small note + large close parenthesis] from individual glyphs?