Well, after a slow and carefully planned execution, IT'S ALIVE!!!
Sorry I didn't take any photos 'Mid Build' but I wanted to concentrate on being carefull and getting things working. The amount of Plastic shows how much needs to be carefully cut from inside the new case. This is mainly to run the wires to the new transponder position.
But the end result is that the key works perfectly. Very happy
Some small lessons/hints/tips learned along the way:-
As previously noted, make sure you get a perfect fit screw driver for the tiny screws. Any movement could strip the heads with ease.
Take note which way up the transponder wires onto the main board. Mine had a clear code printed on it so it was pretty easy. But as with all electronics, there is a small chance that not all transponders will be printed as such.
The transponder is both glued and soldered to the main board. To remove mine I applied heat to soften the solder whilst inserting a very sharp (and strong) scalpel blade between it and the board. The transponder itself is conected by flat plate to flat plate (rather than pins) so it is faily easy to remove if you follow this hint.
Have a drill or hole cutter (I used a hole borer, big silver monster thing in the top of my shot) so you can run the wires for the transponder from within the module. Remember, the module isn't meant to have wires coming out of it, so there is no provision for these. You will have to make these holes.
Plan the above holes very carefully taking into acount where those wires will sit within the new key case (I test fitted 4 times before making a final decision and cutting the holes)
When dismanteling the new flip case be very carefull to try and remember how many turns the flip spring has on it. This just makes things easier, like a muppet I opened mine and let it spin off, cure about 6 attempts of winding and rebuilding before I found the perfect tension for smooth operation .
Take your time.