I'm not aware of any, and I'm not sure just how useful it would be. What one head might classify as a '1' and a '2', another might view as a '2' and a '3'.
These are difficult judgements to make, and it's understandable that there is a lack of consistency between schools.
What may be less understandable is where there is an inconsistency within the headteacher summary sheet itself (a mismatch between the headteacher's recommendation and the headteacher's comments). Cases have been brought to our attention where the recommendation was, for example, a '1' ("exceptionally highly recommended") but the headteacher's statement of support regarding academic ability/potential was distinctly lukewarm!
The actual value of a recommendation may not be the same as its nominal value ,,,,,,,,