This keygen actually works. Run it on Windows. 

Get the hostid from the Irix machine but NOT 
with lmhostid. In the ptc root directory there's 
a utility "ptchostid."  Use that.  On Irix, you 
need to add 00-08- to the front of the host id. 
Strangely, on a Fuel the lmostid was correct, 
on an Origin 300 it barely resembled the ptc 
host id. 

This one works well for wf2. Don't know if it 
will work for earlier versions.