FATAL 2: invalid checksum in control file

I am trying to restore a database from a machine which has died. The
machine was taken down normally but refused to restart so the data has
been copied elsewhere.

The database is in version 7.2 so I installed 7.2.8, but upon pointing
the postmaster at the relevant data directory I get the error in the
subject line.

The databse was originally on a ReiserFS partition and is now on GPFS,
if that makes any difference.

Any cunning tips on how I can get the database back? I have exhausted
my limited technical knowledge.

(Yes I know a backup would ahve been a good idea, however, lets move
on from where we are , not where we might have liked to have been).

..d