Using the terminal type in...
ioreg -l | grep cpu-version
to get the PVR/PID value.
A CPU version of <003c0300> equates to PowerPc 970fx rev 3
A CPU version of <00390202> equates to PowerPc 970 rev 2.2
Don't know what the newer 2.3/2.5/2.7 show up as... 😕
Edit - Use the Terminal, and just using ioreg -l will print everything out.