Ferrari 641/2 (F190) brake duct assembly

I presume quite a few of you allready built the 1:12 Ferrari 641/2 (Tamiya). Or the other two in this series (MP4/6 and FW14B), since I presume they'll be assembled the same way at this specific point.

After the completion of the rear brakes itself, you screw the inner parts of the ducts to the brakes itself (I think parts E53 & 54) with a 1.2x4 screw (think SB4). Try as I may (and I've tried...) I cannot get those screws to pull the duct tight. They don't protrude enough to interfere with a dry-fitted upper halve of the duct (E52), but the looseness of the duct concerns me.

I am planning on replacing the screw with a shorter one, but before I do - is it not maybe the way it's supposed to be? It really doesn't seem very right to me.

Or is there any other ideas? Other than drinking a Red Bull and trying again.