Here's a fixed version.
Draped it onto a surface to make sure it was flat.
The main things wrong were the parallel lines didn't often meet the faceted curve - fixed by copying a long line at the centres drawn multiple times, overlaying existing lines and auto-cutting curve's edges, then deleting unwanted bits (v7 auto cuts intersecting edges). A few unconnected vertices and strange overlaps didn't help.
Make Faces was not needed that much once that was fixed...
There are still a few messy bits around the circular shape - suggest you might redraw that over the top [in a group], then erase the unwanted mess and then explode group to insert the good circle etc ?
Note this version is stripped down - no layers, materials etc...
H