I'm afraid I'm still unable to comment on the chances of success. It rather depends on the academic evidence as a whole
- including the exact standard of maths, and how strongly (and realistically) the headteacher's statement of support is worded:http://www.elevenplusexams.co.uk/appeal ... cation#b41
It will, in any event, be quite a difficult decision. 115 is unlikely to be viewed as a strong score - but of course the test is solely VR, and you can justifiably point to dyslexia.
The CAT scores at the moment appear to be your strongest argument, ranging from 108 at one extreme (VR) - up to 141 at the other (Quantitative)!
A pity the EP's non-verbal cluster wasn't higher than 121.
Maths is put at level 5, but we have no idea whether that's a borderline 5 or - as we would hope - 5b or preferably 5a.
The more evidence there is on the maths/science side to support the '141 end of the scale' - the better!