You don't need to call them legally if above 2000ft AAL.
It is often said you should, but ask yourself the question of what exactly this will do with Stapleford which has
- no ATC
- no radar
- no obligation to pass traffic info to you
- no means to pass reliable traffic into to anybody (because of no radar)
- no obligation to tell anybody else about you
- without radar, subject to the usual tricks of inbound pilots being "vague" about their position
It is far better to give them a wide berth, say 5nm, and not talk to them. Or transit at a much higher level, say 4000ft AAL, but you can't do that in this case because of CAS.
I never call up aerodromes like that. Can't see the point.