Solarwinds acquired Dameware back in 2011. The first release was version 8.
Any previous version (v6 / v7) was a pre-Solarwinds release, and therefore the license details are not available in the Solarwinds Customer Portal.
If you require your v6 or v7 license details, please contacts Solarwinds Customer Service and provide the following information:
Providing that we have sufficient information to locate the license, we will send you the license details and download link via email.