With regard to the uniform, he did say at the outset that he'd buy a drink for the first person to spot the 5 errors. Shoes, rank on arms, belt (it's actually Army Medical Corp apparently), polished visor on cap and buttons (it's a recent cadet's tunic, so has Queen buttons, not King). I did get them all, by judicious use of guessing at likely things that were wrong and letting him tell me the detail... I got a free manhattan out of it!
Tim, good point about the uniform and archaeology. Cloth is a rare survivor, and there's a lot of conjecture goes into it - which is fine if you make that point and can get people to understand that it's conjecture.
Simon just popped into say hello, he's here for a conference (I'm just putting off doing Chirstmas shopping), and said he got funny looks on the train in - he was wearing his sheepkin flying jacket and reading the birthday present he got from a friend last week - the Haynes manual for a Spitfire! (The plane, not the car). Apparently each wing was held on by 7 bolts...
It was a fun evening, I like fancy dress - especially if I can be subtle, or subvert it a bit.