or create a fresh addressbookaddress and get a reference to it that i can pass into a function that does the work?

Nope. Subrecords cannot stand on their own; they must be created as a component of a Record. Here's NetSuite's explanation of how the API works: https://docs.oracle.com/en/cloud/saas/netsuite/ns-online-help/section_4686991741.html And here's their

addressbook

example: https://docs.oracle.com/en/cloud/saas/netsuite/ns-online-help/section_4687606306.html