Older versions of CC licenses are numerous, and would make for a long list; also, they're legacy. If you own the assets, maybe you could re-license them? Otherwise, try asking the rights owner, they're often fine with applying a newer version of the same license.
Failing that, you can leave the drop-down at the default N/A position and mention the right license in the description; it's not ideal because people won't be able to find your project by license then, but it's a solution. Hope this helps.