This pump was removed from a 6/1973 HQ Melbourne built.
The colour found on the rear side of the pump was yellow .The yellow was also present on the ends of the bolts.
This is one of two from the same plant with the same colour.
Click on images to enlarge
Also all these pumps have a series of numbers and letters, as to there usage i have no idea.
This one has 342N
Also note the usage of the star washer on the bolt.