Just a quick update, I have come back from my annual leave, and tonight, glued together the two parts of the LCD frame, so the lilliput fascia plate has just been glued inside the Metra dash plate.
I had a chat to Nexson on the best way to fill all this in, and he had indicated that epoxy was the best bet for it being such a small gap.
I have to fill this, as the bottom of the lilliput fascia actually bulges out as it gets to the buttons, and I just wasn't convinced of my sanding skills to flatten that bulge down, and make it a flat fit inside the metra unit.
So what I have done, is left the bulge in the fascia, which changes the angle the mount sits on, as I have realised it will actually help line the screen up perfectly at face angle when it gets mounted into the dash!
Sorry, no pics on this as yet though, I have used a pretty slow drying (30 hour cure time) 2 part epoxy to do the join, as it will give a good solid join, its thick enough to smooth into a good fill, and should come up nicely. Once I get it out of the clamps, I will grab a piccie and upload, before i start sanding, to prep for paint.