Absolutely no help for your predicament, but with the advent of digital
cameras
(and a lot of hindsight) it would've been wise to take photographs of
the
layout before the final stages to help you locate pipes, cables and the
like.

Similarly, when dismantling some complicated piece of machinery it may
be
worthwhile to photograph the stages of dismantling to aid reassembly
later.
How often have you dismantled something then there's been a couple of
days
delay to acquire a new part and then you realise that your memory isn't
as good
as you thought it would be... aaaargh!

Mungo

P.S. No way to find the wires from the OTHER side of the ceiling?
Remove a few
tiles maybe and fish about?