I'm not sure if this helps or indeed even if I've got this absolutely right, but having come from a background where I too used to soar silently (before now also drilling expensive holes in the sky with a whirly thing), I think there is a pitfall to be wary of here.
I took advantage of the cross credits which allowed me to get from a BGA Glider Pilot Licence (GPL) to an NPPL (SSEA) in a minimum of hours (approx 12) with the intention of then further upgrading this to a JAR / EASA PPL. Provided that the NPPL training you have had was with a JAR (not BGA) rated instructor then I understand that I can count these 12 hours towards the 35 you need to get from a GPL to JAR/EASA PPL. If on the other hand I'd done an NPPL (TMG) with a BGA rated or non JAR rated instructor then none of these would count and if I subsequently wanted to go from NPPL to JAR/EASA PPL the hours spent getting the NPPL cant be counted.
I learnt years ago that 'instructors speak with forked tongue' when trying to catch you out and the same is true of some posters on here it seems, particularly those who may have only recently joined and may have a hidden agenda.
Suffice it to say that I walked away from a certain club / organisation earlier this year who had some of the aircraft mentioned above for reasons I wont go into on here, in favour of a far more professional outfit with a not dissimilar name (at an airfield not far away) and I've not looked back since!