After googling for a while late last night I found a Q&A forum where some guy was asking a similar question and had emailed photo's of the front and back of the Nissan stuff to whoever runs the site. The answer went on to say something about the back of the bottle saying it's OAT based, so I guess that's that mystery solved.
turned out I didn't lose that much fluids anyway. Topped up with about a pint of RO water to bring the level up from Min to Max then topped the radiator up too. Started her up, let her warm up and cool down and the level's were all the same. Mission accomplished, and no drama's for a change