I'm afraid not as the plugs are different, as are the mounting brackets!? Plus the speedo is digital so you'll need a speedo cable from a 'normal' MK2 to get the speedo going.
Take the 'digifitz' as its called out and have a good long hard look at it, check for dry joints, broken traces on the PCB etc.? There might be a voltage regulator on the back, if so test it like so:
Voltage stabiliser
To test the voltage stabiliser, connect a voltmeter between the terminals shown (see illustration) with a 12 volt supply to the remaining terminal. A constant voltage of 10 volts must be registered. If the voltage is above 10.5 volts or below 9.5 volts renew the
voltage stabiliser.
