I’ve just looked at the Aerodynamics pages and found a couple of them :
The two drawings about endplates
The drawing of the diffuser.
Hope this helps, I’ll post again if I find some more in the other sections, anyway it’s quite easy to recognize them, just look at the style and at the signature
the two drawings showing the brake ducts of McLaren and Ferrari
The drawing of the Stewart tub, the signature is missing but it looks really like a Piola drawing, if I’m not mistaken it’s in one of the books, judging by the horns it should be the ’98 car, but I’ve to verify it this night at home.