score beginning at end of first page of a bookpart

[Ali Cuota]

Hello Lilyponders,

I have a (I suppose simple) question about layout/paper.

I need ta start a score at the end of page (in one case one system,
other cas 3 systems), but I dont know how to fix it.

Actually, the page with one system is vertically overstrectched (but
how to fix systemspace only for one / the first system?

And in both case, how to get a ragged-first-top = ##f ?

Thanks in advance,

Francois