If you go back to when BA bought BCAL, Loganair was one of the airlines that applied to the CAA to replace BCAL on GLA/EDI to LGW. To bolster their case they acquired two 146s with which they proposed to operate the routes. However the route licences were awarded to Air UK instead and Loganair were stuck with the 146s which, IIRC, they mainly operated out of MAN. I think I can say with certainty that that was the end of Loganair’s interest in Scotland - London routes.