I strongly advise you to stop using the term "anti-gravity" the way you use it in this piece. There are any number of physical mechanism for COUNTERING the pull of gravity, but that does NOT make them "anti-gravity". Properly construed, "anti-gravity" is "negative" mass. Such a particle would repel regular mass, and like "positive" masses they would be attracted to each other. Inertially, positive or negative would behave the same.

(When we say "anti-particle" we actually mean anti-charged particle.)

Did Telsa ever actually use the term "anti-gravity". If he did, please provide a quote.