'72 Meter Cable Connectors
H2 meters have angled drive, H1 drive is straight.
'72 Meter Digit Colors
All H2's to approx VIN 18,300 had the Olive Green digits, they then went to Torquoise (?) digits and then on to Blue around 21,000 - H1b and S2 also had the same changes to the colours in the same manufacturing period. - Rick Brett
Green, Turquoise, Blue below (click pic for full size):
S1/S2 KPH Meters