This rum-based Negroni may make you wonder why you've been drinking gin Negronis all these years. The Right Hand is usually served straight-up in a coupe...
I found it excellent as specified, using Haciendo Saruro Ron Añejo (Venezuela), Cocchi vermouth, and “Red” aperitivo by Forthave Spirits (Brooklyn NY).
Quinine and aged rum is tricky. Had pretty good luck using 1.25 oz R.L. Seale 10-year-old (though I now think white rum would work better), 1 oz Carpano Antica formula, and 3/4 oz Martini & Rossi Riserva Speciale Bitter, which is a bit less quinine-dominated than Campari. Used a really big orange twist and dropped it in since no orange wheels. Not sure that the Xocolatl bitters are helping; this has plenty going on as it is. The real question is whether/which rum works as a base for a Negroni.