Hmmm,
I wonder if someone at D&C was a tad creative about what was and wasn't destroyed, thereby earning themselves a few bob on the QT? Don't forget the FOI is a relatively new thing and at the time the Enforcers were disposed of it was probably never envisiged that questions would be asked.
I'd love to hear your thoughts on this one Alan, PM me if you don't want to put them in the public domain.
Cheers,
Simon.