Re. MAN-LAX
We were given some figures at a meeting I attended last year of unserved and underserved routes from MAN. These included pax who flew from/to MAN via another hub and those who didn't use MAN but were from within the 2 hour catchment criteria. The latter were classsified as leakage to London airports, so may not have included pax from say LBA going via AMS or say from BHX via DUB.
Afraid I don't recall the actual numbers but what was rather surprising, to me at least, was that SFO was about 5th in the list of unserved and underserved routes and LAX didn't make the top 10. New York was the highest followed by Bangkok and Hong Kong I think.
Of course, the 2 hour catchment is a bit misleading as passengers within that area from the Midlands may well prefer to fly from LHR to New York for example with the vast frequency of flights and choice of airlines.