Can it not be
buffered and level-shifted? 
 I'm sure it can be.  I only know little bits about video magic, so it's
 beyond me to design a fix.   I would not be adverse to building an active
 buffer, but I have no idea where to start.  It should be powered by
 either +5VDC or +12VDC to minimize hassle when connecting the VIP to
 the VR201 in the first place (one needs one voltage, the other needs
 the other; why add a third voltage unless it's something like -5VDC). 
 
Ethan,
Easily done,  pick off a 5V to -9V DC to DC converter unit from NIC
that has BNC connector.  Completely self-contained, feed it w/ 5V and
you get -9V with decent current since that coax RX/TX IC ran hot.
Cheers,
Wizard