Lawyerboy. .. .This is something I can sympathise with, in fact I frequently use the overhead at Stapleford as a turning point. When I call up Stapleford Radio I normally use the rhetorical quesion approach eg 'We'd like to transit through your overhead'. . .. .I'm not expecting any specific reply, especially not any kind of refusal/permission. The A/G guy normally obliges with airfield information and details of any known traffic, especially coming in the opposite direction. For me using a question is a good combination of politeness and giving the other guy the chance to come back at me with anything pertinent.