"Getting the choral score done" on Saturday was, in a sense, true: I had reduced the five staves of the brass quintet to two or three. And (what I suppose I ought to be able to adjust "backstage" in the Sibelius settings) manually overriding, system by system, the peculiarly large space Sibelius puts between the bass clef staff of the organ manual, and the pedal staff. And a few obvious layout adjustments (e.g., where the final measure of a system was a key and tempo change).
I had also made efforts to re-flow the pages so that, where possible, more than one system should fit on each page. The first attempt ran to 43pp., perhaps six of which still only had a single system. The quick-&-dirty "fix" for that was, to try reducing the size of the staves. Although there is a decimal place in that field, I seemed here bound to select a multiple of 0.5, so the reduction was not to so fine a degree as I should have preferred . . . but the result was a choral score which ran to only 36pp.
That, then, was the state of the project when the weekend drew to a close.
Before taking the choral score to press, though, I wanted to compare the two, which I did Monday; and I found that the smaller staves were a significant inconvenience, compared to the 43-pp. score. Yesterday, then, I closely proofread the larger-staved score, discovering a few further tweaks. And today I have a finished score, suitable for placing into the hands of my choir (and on the music stand of our organist) which stands at 41pp.
And we are thus ready to begin rehearsing the piece at tomorrow's rehearsal.