Tried several times to reset the above router to default and the web page standard password admin/admin would not work, did manage to get to a user page using user/user but had no admin permissions. 

I found that I could log in to an SSH session using the default IP and admin/admin and after typing 'help' received a list of the commands available. 

An admin password reset is then possible which then gives full access to the web config.

Hope this helps someone else.