By now it’s over….I hope it went well!
This kind of thing happens all too often. I found that when a booking agent is desperate for a harpist, they will often say whatever they think you want to hear, to get you to agree to play the gig: the part is not that extensive, it isn’t hard, etc. When the music is finally delivered (and that often happens at the last minute) it is enormously long and monstrously hard! Or illegible, or unplayable, etc. I never thought of charging extra for all the modifications that must be made to make a part playable, but it’s an intriguing idea….