So I finally got my hands on a Nokia TMN-1 900Mhz NMT phone.
The hero of the story:
It indeed is the genuine article!
The unmodified insides of the phone.
902MHz PA filter jumpered crudely.
TX and RX VCO's before modification.
Original 900MHz duplexer removed from the left.
The handset with the screen cover removed, exposing the screws.
Handset carefully opened up, the EPROM removed for reprogramming.
Mainboard with the EPROM replaced with one that has the hamsoft.
Successfully running the hamsoft!
Original PA hybrid removed.
How the newold PA would fit in.
I'm yet to make a proper power cable for it.
Oh yeah, and making a qso with the thing!
Picture dump of the process: