Thanks everyone for the help.
Managed to get an install of 4.7 from my audio dealer. What a horrible blast from the past when I opened Mezzo.
A few tips for anyone who needs to run Mezzo 4.7.
Mezzo works best with a clean install of OSX 10.4.0 Tiger and a PPC ( Mine was a G5 Dual 2.5Ghz with 7GB ram ). I used a Sony STD 10000 DDS-4 Drive with an ATTO Express PCI UL3D card. I had Mezzo 4.5 and 4.7 assets on my iLok.
Important to install:
osx_drv_epciplus_321.dmg
Configuration Tool 3.07.dmg both available from the ATTO site
http://www.attotech.com/product.php?model=41
and the current Pace drivers.
Much to my amazement the restore went completely without a glitch especially as I was restoring Mezzo 3.x backups.
Hope this is of some help and thanks again for your input.
Andrew.