Mirroring IK rig / custom shapes

I’m creating a custom rig. For the arm rig I created my FK/IK bones and then mirrored them to the other side (duplicate objects, scale on the X axis and hit -1)

Everything came over fine with the exception of the hand rig. For reasons I can’t understand it seems to be incorrectly aligned. I’ve used edit mode to move around the custom shapes but no matter what I do the control bones won’t go to their correct position.

I’ve added images. If you need more images please let me know. Thank you!

ik-2ik-3