Ambitus placement

[Simon Albrecht]

Hello together,

I like to use the Ambitus_engraver in choral scores, but I often find it 
confusing to read, since the ambitus is printed before everything else, 
although its meaning depends on both clef and key signature. From the 
manuals or some snippet I took the idea to \set Staff.key-signature = 
#'() and thus have every non-natural note in the ambitus get an 
accidental, but the context property was changed (?) to key-alterations 
and now this doesn’t work any more.
Thus I’d like to place the ambitus just before the time signature, after 
clef and key signature. How can I do that?

Thanks in advance,
Simon

Tiny example:

\version "2.19.8"

\score {
  \relative {
    \time 3/8 \key c \minor
    es'8 g c
  }
  \layout {
    \context { \Staff
      \consists "Ambitus_engraver" }
  }
}
%%%%%%%%%%%%%%%