Fitting staves on the page

The basic issue I'm having is that I can't fit the right number of staves on the page without messing up something else I want to stay the same. In the attached score, I would like to change the settings so that the two full staves on page 3 fit onto page 2.

HOWEVER:
- I don't want the number of staves on page 1 to change (thus changing Page settings>Scaling>Staff space doesn't work, because shrinking the space added too many staves to page 1)
- I want the measures per staff to stay exactly the same as they are now (i.e., the last staff on page 1 begins with measure 65, the first staff on page 2 begins with measure 70, etc.)--thus stretching/shortening the measures is not an option

The reason for these particular requirements is that I'm reproducing a part that needs to look just like the original published part, except that when I've finishing reproducing it, I'm going to transpose it in MuseScore. Which settings should I be changing? I'm using the latest version of MuseScore 4 on Windows.

I've seen a number of posts similar to this, but changing any one setting seems to do nothing or to have unintended consequences. Thanks,