Hi Tomi
Not sure how accurate you want your 3D model, as I noted you have 3x3 nuts on this cover. Anyway I just finish the lower engine covers and there 5 nuts along the lower edge at equal spacing. And 5 nuts on each side of the cover but not space equally. The nuts in the
orange area I am unsure of, as I have not see them in any pictures yet.
Happy drawing, Simon.