Just an observation. The so called “primitive” people who made instruments like these relied on them to regulate such vital timing as planting, or gathering and laying up stores for winter. They may have also used them for timing celebrations or festivals worshiping the gods. Therefore they display remarkable accuracy. Anything less would be useless. Modern fakes tend to feed into the notion that the primitives couldn’t make basic astronomical observations, and seem to me to be deliberately “crude”.
Certainly Chaldean astronomers of the Second Millenium B.C. had a far more sophisticated knowledge of astronomy than most college graduates today, but that doesn’t seem to affect their vacuous chronological snobbery.