Initially made with Plantation Dark - the PX displaced the rum in leading the flavor. I remade with Coruba and now I get the Trader Vic vibe - loads of potent burnt sugar notes from Coruba dominate the taste - definitely a tiki-type (notwithstanding the nod to the Caribbean region in the name) cocktail from post WWII era.
I note that this is only 2 dashes of Bolivar bitters and a twist on rum selection away from being identical to the "Black Mesa". Maybe the Black Mesa was derived from this, or maybe it was a very similar cocktail that emerged independently - I found the formulation for the Black Mesa to be slightly more interesting (I think that is nearly all due to the rums I selected - Appleton 8 and Smith & Cross, I believe).

A fascinating and intense drink. It is definitely more than a sum of its parts. It starts with cocoa and coffee notes which leads to some rum funkiness and then on to orange flavors. It mellows nicely over time with some dilution from the ice. I think someone would be hard pressed to guess the ingredients. I made with Smith and Cross rum.