wire that goes from 90W Power Adapter a1097 to apple cinema hd display

The wire that comes from the power supply is tethered, meaning non-detachable, so I don't see how it can be lost. Or maybe I am misunderstanding. Is it the AC cord that is missing, e.g. the one that goes into the wall? That should be a normal IEC 320 C13, which is commonly available. You don't need the Apple one.

This white box then has a input on the opposite side that should go to the display. It is that wire that is missing.

That wire is permanently attached to the display.

Malcolm,

Thanks for correcting me. I had it backwards.

To the OP, either way, it's an attached cable so it can't be lost.