These are some ideas from Jonny, who has been working hard behind the scenes:
Soprano choir and soloist parts are together and are at different volumes. I am not sure that they are consistent though.
I think that Measures 216 to 330 seem to start on the bottom system of page 10 and finish on page 17.
I think that Measures 541 to 762 seem to start at the top of page 25 and finish at the end of page 46.
I think that Measures 782 to 842 seem to start at the top of page 48 and finish on page 53.
I think that Measures 851 to end seem to start on page 55 in the bottom system after the 4 bars rest and goes to the end.

Steve has kindly produced a translation and pronunciation guide for Bogoroditse Devo and We Praise Thee.

Some recommended links from Katy Garden on breathing and singing, after our workshop.