I know this is an old thread, but in case others feel as I do that these old analogue gauges are both nicer to look at and quicker to read than the modern LCD equivalents I think it should be relatively easy to generate the sine/cosine voltages required by the wind direction instrument with a DAC (digital to analogue converter) chip and a small MCU (microcontroller unit) such as a Microchip PIC or Atmel (a.k.a. Arduino). The MCU could accept
NMEA 0183 messages over its
serial port and convert the wind direction data (e.g. $WIMWD) to the corresponding sin/cos voltages. Similarly, it should be easy to generate pulses for the wind speed instrument from the same MCU. You would need an
NMEA 0183 data source of course, such as an
Autonnic wind sensor, and basic programming skills.
Edit: Found a company called Tinley
Electronics who produce exactly this type of
hardware, specifically for old B&G gauges:
https://www.tinleyelectronics.com Rather pricey, but saves having to build your own.