Dave, when building my DH.9 I have opted for wooden plate on the bulkhead and metallic colour for the cross bracing. Do not ask me why, please. This just came out so. Unfortunately, I could not find any photo showing open engine bay of DH.9. Pity, because there are a lot of mysteries. Sometimes I wish, they opened the engine in the Le Bourget DH.9. But then, it may be lacking the details, too. We will never know.
Also the presence of those three holes in the upper part of G7 is hard to explain. I have released my imagination and used the one on the left hand side (looking to the rear of the aircraft) to pass the control rod for throttle and the pair on the right hand side for the fuel lines.
I have omitted the placard decal 96, but my DH.9 served in Poland so it might have it removed if it had it at all.
BTW, how have you solved the mystery of contradictions between photos and instruction schemes for carburettors? In page 6 there is a photo showing the engine top and carbs of Le Bourget DH.9 with the title stating they are Zenith carbs. But they resemble the parts E19 which just below are called Claudel Hobson carbs! I have reckoned, that my DH.9 had the engine block with flat rectangles at the heads of intake manifolds, so I combined E17 with E19, as per the photo of Le Bourget DH.9. And thus found the problems with fit of the parts E3.