I always thought it was the highest level of qualification that you had that counted. An HND in Aero is pretty good considering some of the folk I know applying for jobs in the industry. Oh well, shows what I know!
If you don't mind me asking, how old are you that you have to go 'back' to do some GCSE stuff? Were they particular about which subjects had to be over the C level? Maths etc? If not why not pick bloody pavement cleaning or nose picking?
I would think that if they are asking you do these things in order to be eligible, then you would prob get past the stage. Otherwise I would imagine they would have said, not interested, **** off please. With smiles all round.
