A VFD is basically a valve (tube), they work off high voltages and require a heater supply. Probably the best idea is to measure everything you can off the old VCR - some of them actually use a small inverter to provide both the high voltage and heater supply (often in a metal can - so it's easy to remove and use). You will also need high voltage drivers to feed it, bearing in mind most of them are multiplexed as well.