You're right Wez, there was an access point from the concourse on to the terrace. The door was just aft of the "Brabazon Suite", which was situated on the right hand side as you stood under the chandeliers looking toward the apron. The door was between the suite and the newsagents and gave access on to the terrace in the enclosed section, (where PB Enterprises hovered), a few steps up from the little shop.