Does anyone have any thoughts on ways to revive the heat holding capabilities of thermal coffee servers once they've lost their vacuum?

We have a stack of Fetco L3D-10's that no longer hold heat.  The inside holding tank and the outside layer are sealed together and a vacuum between the two is created to form the insulating layer.

Fetco of course says they have to be replaced.  These things are expensive and we're having a hard time trashing numerous servers that look from the outside to be in near perfect condition.  Especially when it involves $1000's in replacement costs.

Any thoughts?
Thank you.