Update
Finally received my reply from the CAA, so I can confirm:
1. As a SERP you are credited theory study but not exams, and credited flying experience but not skills test towards a PPL(H).
2. Only military hours logged as P1 Capt or 1st Pilot non-Capt can be counted towards the PIC requirement for a CPL(H). Military hours for check rides and flight tests cannot be used.
3. Military hours cannot be adjusted to allow for taxi time to count towards a licence or class/type rating.
If anyone wants me to forward the full response in a PM please let me know. So, back to the study....