I would be very grateful if anyone does and can let me know. It's probably near SW or Central London, boys or co-ed. Has a senior school, I don't know about juniors.
Uniform is blue shirt, dark trousers (helpful). The main bit of details is that logo or crest is a sword pictured upside down, with some sort of yellow ribbon at the bottom that looks roughly like a W shape. I would recognise the logo if I saw it again!