WindSheer,
Hailing from that neck of the woods myself, I can assure you catagorically, unequivocally, 100% that ALL scarebus wings are indeed maunfactured and assembled in Broughton. I think Filton make various other components, but not for the wings themselves (I stand to be corrected on that last sentance!)
Time to claim those pints from your mates methinks!
Regards,
Cuban_8