I don't think this ROM is a fake, it's more like an unsupported prototype that someone did long ago around the time of OS 3.5 that incorporates certain library updates including cybergfx. I think this was put together for a technology demo of prototype hardware that was never release (that amiga that looked like a toaster box I believe).
If you want the real story on it, load it up and start looking at the libraries that are resident with it. It's quite interesting from that perspective.
