Hey, thanks to all for your help, much appreciated!
I did come across some decent images of the Universal Zoom Finder.


The scale close to the eye piece sure looks like subject distance (in meters) and I don't quite understand how it could be parallax correction (as you say ic-racer).
However, more importantly if Zoom Finder doesn't work as a tool for calculating distance which then can be used to set the camera focus, then it's a darn expensive framing device!
I looks like the VH-R is the one for me. If I can find a reasonable Zoom Finder, it might be fun to have around.

I will definately be looking for one of those rotating backs keithwms, they look very cool.