I used exactly the same Mezcal, and also the same ginger beer. Even though I measured all the ingredients, I eyeballed the ginger beer. Ended up using around 100 ml so around 3 and 1/3 ounce. It turned out delicious, however the colour wasn't very appetising
I just calculated that if you mix equal parts of 40% ABV rum with 69% ABV rum, you get exactly to 54,5% ABV. Not sure if this repliates the flavour well, but if you want to try the cocktail and you don't have the navy rum in your bar, you can try this instead
I'm actually amazed. I've never seen a cocktail using this much of Angostura, so although I expected the cocktail to be completely dominated by it, I was still intrigued and tried it today. Surprisigly the amount of Angostura isn't overdominant at all! The flavours work so well together that I can feel every single ingredient I used. The ratios are also perfect here, there's nothing I would change about this recipe.