Although the scoring system is rather complicated, (See posts relating to standardised scoring) in Lincolnshire the Grammars also look for the top 25%. I have been told as a rough guide that the scores should be around 75% + VR and 45/60 NVR. However the NVR test actually had 65 questions and this was the first year NVR had been used. I don't know how the tests in your area are affected by weighting and you also have an extra test. Sorry I cant be of more help
but it might give you a rough idea.