The date code is visible however if you are wanting the most authentic representation then given the other dates you gave it should be closer in the same range but prior to the engine assembly date. The dates are only a consideration at the highest levels of concours divisions . If you are not going for the division where genuine original correct dated tires,battery belts etc. are required then the correctly dated smog pump is over kill. If concours competition doesn't matter and you just want a more accurate representation then you know the general dates to be looking for .