I have been building NBTVs for about six years, I tend to build one then pull it apart to build the next model. My current version housed in a home built Perspex case and this YouTube video shows it in action.
The two black vertical lines across the picture are caused by the differences in frame rate between the NBTV and the video camera. The picture size is about the size of a large postage stamp.
The new laser cut Perspex case was designed to house all of the circuitry for a colour version based on the American NBSC system. Each section was built on strip board and mounted vertically in a slotted rail in the back of the box. All went well, the picture synchronised quickly and the colour system was almost there. Then disaster struck and for some reason the picture just would not synchronise, I suspected that something had gone wrong deep inside the main wiring loom and it was impossible to track down. At this point I put the project to one side.
Almost a year later I redesigned the whole electronic section.