VSS label file format request

I have a VSS database that uses Labels to identify builds. Users
typically use these labels to get, checkout and share code based on
the labels. This week a number of users reported they cannot perform
these operations against some of the labels.

My understanding of VSS is that label information is stored in the
'data/labels' directory of the system. Looking at the last backup of
the database (done on Dec 29, 2007) there are approximately 1500 extra
files in the data/labels directory of the last backup, than in the
current, live database.

Does anyone on this list have info/ideas/links that can:

a) Describe the format of the data in each file in the labels
directory,

b) Help me rebuild or recreate the missing label files.

Thanks in advance,