Copying ENTIRE instrument, including key signatures

[Ryan4111]

Hi all,

I'm using Sibelius to create training material for a choir. Whenever I import music, i.e. with PhotoScore, I end up with the following "instruments":

• Soprano / Alto
  Tenor / Bass
  Piano (left hand)
  Piano (right hand)

My target score would look like this:

• Soprano
  Alto
  Tenor
  Bass
  Piano (left hand)
  Piano (right hand)

In order to get there, I need to split up the dual-instruments (i.e. Soprano / Alto) into their respective voices to mix them properly. The way I do this currently, is to add a new instrument below the S/A one, then copy and paste the notes, filter out the ones I don't need, and voilà.

Now, my problem is with key changes, or pieces that are not in C-Major: Upon creation of the new instrument, it doesn't have a key signature, and it is not properly copied / pasted either.
When I try to do a system passage selection, unfortunately all instruments are selected, so that does not work.
Any idea what I can do to properly copy everything from one instrument to another?

By the way, I appreciate anyone staying on-topic here. I do not appreciate any generalistic advice on the workflow itself, I require this for a number of reasons and it is not subject to change.

Thanks in advance,
R4111

[MikeLyons]

The simple answer is no. You can't copy your structure in a blue box selection.
I am completely puzzled as to why your key changes aren't following through with new staves - unless there's something wrong with the original ks. Is it, perhaps, a "one staff only" ks? Before doing anything else, try inserting a new ks at the very beginning of the score. This should change on every staff.

Suggestions for workarounds:
If you know the bar numbers, set up a blank template with them (and possibly system text) already inserted, then filter/copy/paste into that.