Thanks for the kinds words fellas, appreciate it. No need to spend a whole pile of money. This was a BrickLink project with the important bits purchased through Lego. I think with the lights I came in around the $750-$800 mark. All new parts and 100% accurate color. The only things I don't have is the 30th anny sticker and the certificate.
Not quite like your attempt although I like your method better. Yes you will need the 2x3 clear plates but also get some 1x2 clear plates as the 2x3's are hard to find and there is no need to have 3 2x3's stacked on each other when you could stack 2 on top of the 1x2's. Your lights need to be dead center to each of the blue/clear plate packs or the lights will be seen at angles.
Yes I removed the existing technic beams and replaced them with connectors to attach to longer beams to so the lights simply just plugged into the back. The path from your lights to the trans clear engine modules needs to be straight on and center, so when aligning the beam in the back there really is only one place it can go so it all works out.
I used trans-clear, they give a "jewel" sort of look into the trans blue tiles.
The only issue per se was the outer most engine modules because they have the technic lift beams attached to connect to the main structure for support. That lift beams on each side need to be there but I think I rotated mine and moved it over a hole to make room for the lights. You'll see when you get to that point. I'm a Technic guy so I have a ton of Technic bits to choose from, if you have some kicking around it won't be a big deal.
Build the whole thing first though so you know how and why it's put together the way it is then do your modding.
I'm sure you will all find a better way of doing it. In the end though what ever you do back there won't be seen, the structure hides it all very well.
The unofficial, maybe not required depending on your style Parts List:
Battery Box
Lights
Extension Cables
2x3 Trans-Clear Plates
1x2 Trans Clear Plates
Technic Beams (1x13??)(1x5??)
Technic Connectors
Awesome! thank you.