Managed to get the category to stream and post kindย  to (tanzawa) post kind mappings working. I also got the attachment import records saving properly.ย 

My basic plan for importing attachments is as follows. Each photo in Wordpress is exported as a post with the post type as "attachment". The guid for the item is the url for the attached file. So, I've created a record has a foreign key to the originating wordpress import record, the post guid, my own uuid, and a nullable foreign key to the resulting Tanzawa file attachment.ย 

Once the file has been imported, I'll have a Tanzawa file attachment set so I'll easily be able to pick up where I left off.ย 

Also since I'm keeping the originally uploaded Wordpress export file around and references between Tanzawa data and imported data, as I add features and capabilities to Tanzawa, I'll have the option to go back and pull in meta-data from Wordpress that I skipped on the initial import.