Thank you so much for the kind words and the acorns.
That sliver alone would be enough to tell an aloe nerd exactly which species (of the 500 or so in the genus) this plant is. So it's a signature thing, a 1 in 500 thing, the thing you look for when you want to nail down the ID. Distilled essence of marlothii, as it were.
So much info in so little space!