Disco 2 handbrake rattle

At around 2500 rpm i get a metal on metal rattle from my handbrake drum, when I put the handbrake on the noise disappears and the noise is a lot quieter when I slacken off the tensioning bolt at the back of the drum. I have taken the the drum off to have a look but cannot work out what is causing it.

Has anyone else had this problem before?

Thanks in advance

See here for answer and technical bulletin that applies to this.

https://www.landyzone.co.uk/land-rover/handbrake-drum-rattle.328134/#post-4222102

Tony