Thanks for the extensive write up of the glcd library inner workings.
I guess I'll be reading for the coming few days hoping to see the light somewhere at the end 
From what I've seen so far is that the T6963 can do what the KS0108 can do and has some additional features like Cursor style setting, and display mode setting (OR,AND,XOR).
The hardware interface is slightly different (no SCEL pins and separate pins for Read and Write and a Font select pin)
For now I will hardwire Fontselect set for 8x8 font and for splitting the RW control into separate R and W lines I'm thinking of using a simple transistor inverter.