What Antheil says and what actually happened may, in reality, diverge considerably. Antheil evidently knew exactly nothing about what was going on, except for his knowledge of player-piano mechanisms. The invention is what it is -- nothing more and nothing less -- than a cumbersome mechanical mechanism that had no further influence on anyone. His autobiographical account of events is highly dubious.

The key to inventorship, as defined by a patent, is whether or not someone contributes something to the intellectual conception of at least one of the claims. Unless the "practical implementation" makes its way to the claims, the "practical implementer" is not an inventor. Note the drawings that accompany the Lamarr patent -- anything of substance was contributed by their helper (a tenured professor of RF engineering at CalTech), who is NOT listed as an inventor.

So I ask again: given that Hedy Lamarr made no pretense of knowledge of the player-piano mechanism, and that each claim is tightly interwoven with player-piano mechanisms, what, exactly, did Hedy contribute? This is, of course, a rhetorical question; we shall never know the answer.