CB
Crossing the Coast southbound in your area the Sectors are split vertically, as you rightly point out, 135.32 and, above FL330, 135.42, you may be missing some which are climbing out of Stansted, for example, which may still be working the London Middle Sector (LMS) passing the coast on freq 132.45.
The northbound traffic you are probably seeing are those entering via sector19 (Hurn East 135.05) which route from BARLU (near Cherbourg) to KATHY (just south of the IOW) then turn to MID - OCK and GWC. These include flights from Spain and Portugal (amongst others!) to most of the UK and sometimes beyond!
High level overflights will eventually arrive on 135.42, medium level flights inbound to Birmingham and East Mids, for example, on, 132.45. Aircraft inbound to Luton and Stansted cross the coast at Chichester at FL190 talking to 127.95, and those at the bottom! FL130 and below are probably into Gatwick on 133.17.
Enjoy the sights and sounds!
