AKWindWatcher I saw on Facebook something about this. It sounds like people have been hunting for it since at least 2022. I hope he finds it.
I did run across Mingus Millie B this year which I hadn't found before.
Also, Janet Riley at the farm which was previously Mike Iler's (Riley Blossoms) had some unknown variegated collarettes listed in the 2023 catalog. Very possibly not a lead at all, since they are probably just his own seedlings, but you never know.