ridevintage aka mike had the cover come off 1 of his previous disk drives & managed to re-glue it,so it'd be worth asking him.
tioga used to make a kevlar cord repair kit that could be used to repair short sections. the issue with disk drives it that the cord tends to get damaged via small cuts in several places (eg top left in your picture) & that causes the cord to loose tension & ultimately the disk to fail.
on the lower left of your picture the cord should pass around the alu "button" thats attached to the spoke nipple
The other place worth checking the cord is where it attaches to the hub, IE under the black circular section around the end of the hub shell. the cord has to pass around a tight 180deg bend & they were prone to break in this area.
the easiest way to check cord tension is to clamp the wheel in a frame & try & flex the wheel sideways, if the wheel flexes easily with very little resistance, then you've likely got cord issues
was this the recent 590Euro disk drive off ebay?