Let's not forget YUL!
Just checked BA.com, LHR-YUL appears to be going from 7 to 10 flights weekly, with BA45 operating on Thurs, Sat and Mon, with BA95 operating daily.
Ditto for YUL-LHR. BA44 operates on Thurs, Sat and Mon, with BA95 operating daily.
BA.com is showing 777s on all flights. It had been mentioned here earlier that the additional 3 flights would be 767s.