Very sorry to hear your plight. There is a current thread about this problem on `flyer forums` - called `yak permit renewal` I think. Presumably you have tried the Richard Goode and Yak UK organisations for help. David Young of Aero Anglia at Elmsett airfield in Suffolk arranged the paperwork for at least one Yak 52 last year so he might be worth a call (I dont have his number but it should be easy enough to find) however I know it was a long process. If you do have any breakthrough I would be interested to hear as I have friends with an aircraft suffering the same impasse.