I think you are making things a fair amount more complicated than necessary by moving the primary I/O to the 5ABOB
I would leave the primary I/O on the 7I76 (step gens limit switches etc) and only add the MPGs to the 5ABOB.This way you can retain the pncconf configuration for most all machine setup and only need to edit the hal file to add the MPG support
Otherwise you have a lot of hal file editing to do