"Does anybody know the exact configuration of how the good old stable belt should be worn..?"
Well...
The Summer camp season for the ATC starts in 8 weeks,
I'm sure THEY'LL be able to tell you how to wear the uniform of the Royal Air Force!
But for the record,
The blue band goes on top (blue to sky)
The leather "buckle" goes on the left hip
And it doesn't matter where the silver bar goes
(although it looks much smarter when inline with the buttons of the shirt)
Regards,
Reg Bitch.