Any advice? Stage opera concert-1 week to work on it!

[SMfairy]

OK, so I'm wondering if any of you lovely people could give me any advice.

Last week I got asked to stage manage for a staged concert performance of The Beggars Opera, with a second act of scenes from other various operas/operettas. The show is a one-off at a big opera festival on Saturday, with a second performance in a small community theatre in the town in which we have been rehearsing. I have been in rehearsals all this week, and we don't get into the space until the day of the performance. As I understand it, there will be a professional receiving production team, and their stage manager will call the show with me sitting beside. I have been preparing The Book as much as I can whilst also doing many many other jobs. My worry is that my Book isn't hugely detailed with relation to blocking, as I have not always been in rehearsal, and the actors sometimes vary their blocking anyway. How do you suggest I deal with going into the venue with quite a rough Book, and having to integrate with their in-house team of professionals (I am a student stage-manager doing unpaid work for a semi-professional company at a professional venue)?

Looking forward to reading your advice!