Well it is for sure post 1966 - when Mann Edge bought out Collins and then made "The Collins Axe" as one of their main line of axes.
You can see on yours the forge marks on the poll - that means it was a very crude manufacturing process for axes and hatchets at this time - in the 1980s. There just wasn't a demand anymore for axes as chainsaws had fully taken over the marketplace by this time. With that, quality control was low as it could be because these manufacturers had to keep costs low to hit margin while trying to stay in business with their product lines which were under heavy attack from imports.
I have the same hatchet with the Collins paper labels and such. You can tell it is your basic hatchet, nothing wrong with it. If you keep it and don't touch it, it will be worth something for sure 20 years down the line, especially seeing it has the paper labels. Good find! Merry Christmas!