Changed Pantone colour in Illustrator file
Figured out how to load Pantone swatches in Illustrator, and changed the 70% Pantone Blue to Pantone 7460C, as suggested by the print shop. The C stands, apparently, for "solid coated", because I found 7460C in the Pantone Solid Coated swatch (open the Swatches palette and choose "Open Swatch Library"). It's difficult to tell how close this colour is to the 70% blue CVC, but it's not radically different. I didn't change the text colour of the French title, because that was already a 100% Pantone Process Blue CVC, so presumably wouldn't cause a problem. I also removed the two colour guide squares we'd added last week, because presumably they're no longer needed.
Then I regenerated the PDF version, as well as the colour separation (which now has three pages, one for the black, one for the solid band, and one for the French text). I've created presets for generating each of these. The separation has to be done by creating a PS file then processing it with Distiller, it seems; going direct to PDF resulted in a two-page file, with no page for the solid band.