@riversidebryan
I read the article all the way through and it seems to me that whomever ruled out the possibility of those being a "precision tool" just because the apex balls preclude laying the object flat against a surface--has no familiarity with assembly jigs, and the precision involved has to do with angular positioning.

It remains plausible to me that those things are construction jigs, sizes of which are dependent upon the type of rods used in construction, which means they could also function as adaptors between rods of different diameters.

Also possible that the apex balls function to produce repeatable spacing. Precision isn't as important as consitency.

The imprecision of the features rules out any speculations about E.T.s.