Well I've had a better look, and I definitely haven't got the tool, or a locking wheel nut key. And one of the plastic caps is different to the others, so it looks like I have got locking nuts 
I'll ask the chap I bought it from whether he by any chance has the locking nut key in a drawer somewhere, but in worst case scenario do audi have a set amount of keys like say BMW do? I had to get one for a beemer once and it was very easy & inexpensive, are VAG the same?
I'm meant to be getting 2 of the wheels refurbed next week, good job I checked this out before I got there 
you can get the plastic tool from the dealers they normally have them in stockm they are about 70pence, the locking wheel nut socket, audi have 8 different types, these a £31.26 pence each,i know because i b*ggered my original one up when i changed the wheels, 2 weeks ago, they were in stock as well
Just spoke to my local Audi parts department earlier and they said same as you, if I go down they will find which one it is by trying with their master keys, and even if they have to order it in it'll only be a couple of days. So I can still get my scuffed wheels refurbed hooray! [Y]