Thanks for that, not seen it.
My sighting in Cricklewood would have been one of the slightly more urban sightings going by that map. I took a screenshot of the map from the site above. My sighting would have been close to the right angle-shaped green splodge (Clitterhouse Playing Fields) that appears below "BRENT CROSS" and above "CRICKLEWOOD".
That said, I note that someone in the comments on that site said that they saw a kite over Primrose Hill (not yet shown on the map).
P.S. I tried to post a message to the site with my sighting but my message was marked as spam! Somewhat ironic given the epic amount of spam links right above the message area.