Thank you once again to all of you for your advice and help. The interview was just a one-on-one with the passenger services manager, I didn't have to do any group activities or indeed meet any other applicant. The office seemed a mess but was told it's because they are moving locations soon, as opposed to it being generally in such a bad state of affairs all the time.
I have been offered a training date, and am thinking over whether to accept it, as I still have an interview with Menzies due, and one with Swissport over at Birmingham. The people at Servisair seem very down to earth and friendly, plus they handle the bulk of EMA's handling contracts.