@Zafero Berr said
"Some research shows that the balcony by McVicar-Anderson, the one based entirely on the Unicursal Hexagram design as shown in the photograph, dates from 1886.
It therefore predates the founding of the Golden Dawn by two years.
It may well be that the UC is a symbol used in some branch of Freemsonry - I would suspect that Mr Anderson was in the SRIS, a very Golden-Dawn-like society."
I was just pointing out a source where Crowley would have absolutely learned of a Unicursal Hexagram.
If we're talking about the oldest examples available of the Unicursal Hexagram, see image 3 in the link, from 1588.
unurthed.com/2009/06/21/brunos-mathesi
http://images.unurthed.com/Bruno-Figura-Amoris-307.jpg