Although I haven't specifically tried to do this, it does look like your onthe right track. The com.landesk.uuid file cotains the unique device ID that would be needed for the machine to not get duplicated in the database. And the /Library/Application\ Support/LANDesk/data/slmdata.plist appears to contain the SLM usage data.
Depending on what you use for imaging, you may be able to automate this a bit. For instance, if you use NetRestore, you could have a pre-action script that copies those files somewhere, then a post-action script that puts them back after it has been imaged. NetRestore has some example scripts that are intended to backup and restore user data but those should be able to be changed for the specific files you want to move over.
Patrick is correct the SLM data is stored in /Library/Application\ Support/LANDesk/data/slmdata.plist