I've done Blackpool-Wallasey-Holywell/Flint a few times. If you actually fly over the Wallasey VOR Liverpool may insist on you remaining below CAS (1500ft) but if you stay offshore you can be at 1900ft.
Liverpool may give you a clearance through their CAS (less likely if they are using 09). If you're speaking to Warton on the way down they're usually very good at speaking to Liverpool to pre-arrange your clearance then handing you over.
Manchester LLC is fun but if you haven't been before, good idea to take a look at the photos online of the various VRPs so you know what you're looking for.