You can buy new sleeves, packing, clips etc from Ducati but they are big bucks.
Guido is sourcing some "quality" wadding, but you can buy normal stuff from several sources. Not that good though.
Have you bust the outer sleeve? If not, drill the rivets and pull the cans apart. Inspect the packing....it might not need changing??..........remove it and have a go straightening the centre section youself??
If you don't fancy it, mail me and we can try and sort something out?
Unless it's a 'mare of a mess, it should sort pretty easily