thanks
Hal
Brick level does not work on public folders (neither does Exmerge)
You need to dismount the public folder before restore- MS298901 article will help you.
You can restore public folders without affecting other exchange function - above article would apply in this case.
Isinteg and ESEUTIL will help in diagnosing and repairing corrupt database stores.
There are third party tools (such as Power Tool) which can do brick level restore from Public Folders - all you need is do a restore on any exchange server (e.g test server), do not mount and this utilty will read the database/folder structure.
Hope this will help/