Problems with FITS headers
You are missing the PC1_2 and PC2_1 elements of your pixel transformation matrix. If your coordinate transformation is a rotation, you would use

PC1_1 = cos(t)
PC1_2 = sin(t)
PC2_1 = -sin(t)
PC2_2 = cos(t)


for the PC matrix. The pixel scale (in degree/pixel, according to CUNITi) goes into CDELTi.

As pointed out, you can combine the PC and CDELT steps into a single CD matrix.

See here and here for more details.