Update:
Had a call from SGM last Friday 12th, although they had received the parts on the Monday they had to wait for a Glazer to come in. Earliest appointment was the Friday they called.
Essentially they have to cut the old roof out, clean all the sealant out, apply new sealant, lay the new roof in and leave it over the weekend to set.
Monday they should do some water tests to ensure there are no leaks and finish off the re-assembly Monday/Tuesday.
The guy is hoping it will be ready Tuesday evening.
The roof is either vastly different to the Bravo's or they're fobbing you off. There shouldn't be any need to remove the rear glass panel if they're changing what you've mentioned to date.