[clug] Re-signing Debian Packages

[jm]

I've run into a problem with a set of legacy systems which are very much 
stuck on an old version of debian for which the GPG package key has 
expired. It's possible to ignore the GPG key and have apt manage the 
packages regardless, but I was wondering if anyone new of a better way? 
The one that comes to mind is, would it be possible to resign the 
packages with a new in-house key? if so, how would this be done and what 
would be involved?

And, to short circuit this suggestion, it's not possible to do a distro 
upgrade.

Jeff.