Welcome Brad,
Agreed...The Original paint code/colour is Avocado made by Galmet.
If your after originality then this is the Colour to get.
The shade has changed a bit ove the years but it still remains fairly close to the original tint.
The reason for the green variations is made up of a few factors. Galmet no longer make this formula for shelf sale,its by order only,and its no longer available in sprays.
There are a wide range of colurs in different brands that people tend to go with for cost and ease of use as not everyone has or will outlay the cost to set up for a spray gun.
The fastidious restorer will sometimes not be happy with the current tint of Avocado as it does slightly differ from 50s examples. They will attempt to get colour matches to find that perfect match....But it often takes a few attempts for a good match and becomes expensive,and it is starting to get to a point where uniformity no longer exists. But with that said each restorer and restoration is by the owners tastes and interpretation.
So Avocado would be your best bet if your going for originality. Also Deep brunswick green in the Wattle Killlrust spray is widely used and a well recognised match for the handlebars,brackets and toe ring assys.
As for your models post some images of the bases and serial no of the engines and we can tell you what goes with what mower
