The easiest way to do this was to go to File → External → Data → Pack Resources
Then File → External → Data → Unpack Resources
Choose Write/Overwrite current
This created the texture folder and imported into Unity correctly.
The easiest way to do this was to go to File → External → Data → Pack Resources
Then File → External → Data → Unpack Resources
Choose Write/Overwrite current
This created the texture folder and imported into Unity correctly.