People have been selling these backlights for AUD$200 but they are made of very cheap easily obtainable parts. The tiny cutouts are alignment notches that match the original backlight coverage. when 3D printed a slicer will creates a wide homing circle for each corner.

to make a complete backlight here is the bill of materials.

Spox 2P connector. you can buy this as a pigtail in case you don't have a specialized crimping tool.
AUD$12 for 20 pigtails.
https://www.aliexpress.com/item/1005005919461420.html

EL foil - the light producing part. If you happen to have a broken backlight then you can simply replace only this part.
AUD$40 for 10
https://www.aliexpress.com/item/1005004185933220.html

insulating tape and/or appropriately sized shrink tube.

thin double sided tape to adhere the EL foil to the backing.