Ducati,
This is a tough one, even when unwrapping the masts and booms from factory we have this issue.
If you have used Acetone and it doesn't come off then i would assume that it has been in the sun for a while and the aluminium as a 'soft' material absorbs some of the glue, tough as it is the only was i have removed this have been:
1 - Acetone
2 - WD40
3 - Lemon Juice
4 - Heavy Duty Hull Cleaner
With 4 you then have to polish up the area again as you will be striping away the normal protection of the metal...
Is the surface still sticky? If so then should be good, if not then certainly has been absorbed.