I dont have specific experience of Humberside however IIRC they offer a LARS service. Based on experience of similar aerodromes I would call them up once clear of Fenton and initially request a basic service.
I was taught CARPACER which in this instance would translate as follows;
Callsign - Humberside Radar G-ABCD
Aircraft Type - PA28
Route - Sherburn to Humberside, routing X Y Z
Altitude - 2000 feet
Conditions - VFR
Estimate - estimating next turning point at ...
Request - requesting basic service
Humberside will then know you intentions, possibly give you a squawk. Once you are closer they will probably give you joining instructions.
If you dont get anything I would call them up about 10 miles out to advise your positon and request joining instructions.
9/10 I find ATC call me just when Im thinking its time to call them.