Morning Guys!
Just checking in to see how my overnight answer fared.
When I saw Graeme's Challenge, I thought (Like Skytrain) that it must be the little feller in the background, mainly because that really is a "Silhouette"! I was going to look into the fact that it appears to have leading edge slats in the open position, so it's presumabley formating on the camera ship, but that's no longer relevant now as HD says. Graeme has closed the challenge and announced the answer as the Vultee (camera ship) . Although he didn't say it in so many words, I'm sure that Open House is what Graeme meant and we should carry on.