General :: Retrieving Files From Damaged LVM Disk On CentOS 5.5?

I'm running CentOS 5.5.

A couple of weeks ago, my 500 GB disk crashed after suffering an accelerating error rate for a couple of days.

Now that I have a new disk in place, I want to mount my old disk, which is (was) an LVM disk, as a second disk and recover files from it if possible.

The question is, how do I go about this?

If I mount the old disk:

# mount /dev/sdb1 /sdb1

the top-level directory shows only two subdirectories:

lost+found, which is empty; restored, which is an image of files recovered from old disk's predecessor.

'df' shows (or appears to show) that the disk is 11% full. Sorry, I don't recall how full the disk was before it crashed.

How do I get the system to recognize the LVM structure on the old disk & mount it?

Or is the directory structure too corrupted? Do I need to send the disk out to a recovery service?

P.S. Have aleady done some poking around with lvmdiskscan, which shows the old disk whether it's mounted or not, and vgchange -ay, which doesn't appear to do anything.