Evalu8ter, it is a long time since I was associated with BBMF (1986) but, unless things have changed radically, the RAF groundcrew do a great deal more than AF/BF. Among other things, they are the ones who check many aspects of an airframe for faults, and I suspect that no one in the RAF at present has the knowledge to declare that a casein bonded joint is serviceable. They certainly didn't in 1986. As for authorising a deferred fault!.........