Upgrade Data from 7.x.x to 8.x.x

Hi there,

Hopefully a simple question.  I have a copy of the data from an old
PostgreSQL installation (it's not a dump, it's a copy of the PGDATA
directory).  I have two questions, is there a simple way for me to
determine the version of PostgreSQL that this data belongs to?
Secondly, is there anyway to import this data into PostgreSQL 8.0
without need to run a 7.x postmaster?

Any suggestions would be greatly appreciated.

Regards,
Patrick

B.T.W.  For those curious, this data came from a RAID5 array in which
two disks had failed.  I spent a week messing with pyflag before I
managed to recover this data.