Yep it accepts anything I need, composite (IIRC this is FBAS), s-video (or y/c) and RGB.
And sound too.
We had a number of the large 20" PVMs at the first Retro Game Experience and essentially this is the same beast only with a very tiny tube.
Gonna have to make some nice cables to make it possible to directly plug in the video connector from arcade harnesses. maybe just one with a couple of connectors.
Just read the service manual and it even has a button that will show you the horizontal and vertical sync signals....pretty useful !