**UPDATE**
For those who have Mental Ray installed on Maya 4.5, and you want to clean up the nasty Mental Ray code for a cleaner 4.0 conversion, here is a link to a NEW mel script that removes the MentalRay nodes from Maya files (.ma and .mb)
by Alin Sfetcu ( Sanctuary )
snct@mymail.ro
https://www.highend3d.com/maya/mel/?section=project#2229
Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS
izzylong.com