Robot motor shield has now arrived. Pictured below.
I am now in the process of setting up the software needed for this. Based on the instructions here. Not that this is a version 1.0 board. SO later models are more updated and need newer software.
Main Documentation pdf file is here.
Further instructions can be found on the Adafruit website.
Along with drivers etc on Github. You justr need to download the zip file and install to the Libraries folder in the usual way.