The aircraft at EXT is in the process of being re-registered as EI-GGC so perhaps that is causing the delay. This is the first of the aircraft that Stobart have bought, the others being G-FBEL/EI-GGA and G-FBEM/EI-GGB. The aircraft currently operating at SEN are dry-leased from Flybe apparently and will be replaced by the re-registered aircraft in due course.