There are also thin ply parts on either side of the fwd spar, and beefier parts that go right at the LE and TE of the wing centre section. For the TE, the part is cut to match the profile of the wing TE, but that causes it to not fit due to the fact that there are large balsa blocks glued into the wing TE (for the wing bolts to go through).

As a result, some quick trimming is necessary to get the patrs to the correct size.