The module has a 2-pin connection at the top just above the 'SMITHS' logo.
Smiths RVI - RVC Tachometer conversion board + calibration cable -566-
Smiths RVI to RVC Tachometer EXTERNAL conversion with calibration cable -573-
JAGUAR XJS V12 (1981-1990) LUCAS NOS 160MPH SMITHS SPEEDOMETER (ES3101-20)
SMITHS NOS 52mm 100psi OIL PRESSURE GAUGE (KIT CAR/RAT ROD/BIKE/BOAT ETC)
NOS Range Rover Classic LHD SMITHS Speedo Cable 579166 GENUINE
FORD ANGLIA 100E (1956-1959) SMITHS NOS 80MPH SPEEDOMETER (SN4473/02)