Your power flying doesn't count to the log book requirements for a Bronze C, and you get sent solo when the instructor thinks you are ready. However your experience of flying might well help you progress faster than an ab initio. OTOH you might have learnt some bad habits you have to unlearn...
I see someone has suggested Lasham to you. It's really well run on the flying side, lots of gliders, two winches, field dries very quickly after rain (chalk I think and a hill top site), plus the catering is excellent and so is the bar which has won many CAMRA awards. However since you live in Lancashire it's rather a long way to go unless you are going to go for a week and stay there!
But there are plenty of other clubs offering well-run training. They all offer training to the BGA syllabus, but the degree of organisation and so on varies. The BGA website has details of all UK clubs:
British Gliding Association - UK Map
And they just about all have a website.
I have a friend who started gliding having a PPL and he made rapid progress to solo and on to bronze - his previous airtime helped him. Hopefully yours will help you as well, and you will also make new friends and discover a fascinating pasttime and you will keep flying through to Bronze, Silver and doing XC flying.