Using \slashSeparator only with forced breaks

[Jens Gyldenkærne Jensen]

Hi all. I'm trying to typeset a choral arrangement where each stanza
is set for different voices (1: SSA, 2: TTBB, 3: SSATTBB). The
handwritten original uses a separator between the first two stanzas
similar to lilyponds \slashSeparator - but in lilypond I can't find a
way to show the separator only between specific systems (e.g. after a
forced \break).

Are there any good suggestions to how I can make a clear visible
separation between the first two stanzas?

(I would also prefer to have the instrumentnames shown only in the
first system for each stanza)


-- 
Jens Gyldenkærne Jensen
Veksø