Heres a possible suggestion.
Following on from someone who pointed their consumer Video camera at their empeg in their hi-fi stack over Xmas last year and used their TV as the display device.

Why not get one of those cheap(ish) Video cameras [I mean those ultra-small pin-hole type cameras that have a composite video output].
then mount it in front of the Empegs display so it can see the whole VFD display [in focus] then route that composite video signal into your regular 'small portable TV' with Comp. video input and/or your in-dash video display unit that we all have in our cars these days :-)))

This would solve the need to do major hacking on the display boards, would be easy to remove and would allow you to mount your empeg where the sun don't shine [e.g. your trunk].

For control you have a few choices:

1. IR remote extender to get your existing/steering wheel Ir signals to your empeg.

2. Some kind of wired or wireless remote on the serial port

3. A Sony Stalk (if you have a Tuner module).