The NEC 1801 pivot most certainly did work with PAL and NTSC. It had BNC video inputs for that very reason and was the default monitor for the DVD Maestro authoring suite from Spruce. I know this as I sat in front of it day after day authoring DVD's. Other NECs? I couldn't tell you.
The 1801 pivot was one of the best screens I've ever had the pleasure to use and would be an ideal Amiga monitor, they are now, sadly, rather rare, as they cost an arm, a leg and a granny when they came out.
