In case you cannot get a used body as a reference,
a tips to help on cut out of engine/filter and body posts.
You work on the tallest object on the car first i.e. engine/filter, handle, and then body post.
You need a lighting touch to do this..........
level the body above the chassis with the engine head touch on the body.
use the touch to project the engine head shadow on the painted body. you might need to rotate the position of the touch to get the engine head profile on the body shell. Mark the engine head profile on the body shell when you are doing so.
so on so forth, do it the same on the next tallest object and cut out before you move on the next object.
Hope this help.