Hey Chippy,
I'd definitely recommend the Swanwick visit, the area and aero jobs seem quite different and with the way things are going at the minute with the cancelling of aero courses at the college I'd imagine that area is the way to go at the moment. If you can fit it in before your interview it'll definitely be a help as well.
I was there on Saturday morning and it was really cool - the crazy weather mean't that the whole building was in overdrive, quite exciting!