No Savoia Rosso so I faked it with 1/4 oz marsala and 1/2 oz Contratto Bitter. That was too tart, though, interestingly, not too bitter, so I sweetened it with some agave syrup and additional blood orange juice. Maybe the Savoia is on the sweet side. The extra blood orange did give it a better, deeper purple-red color and made the blood orange flavor more dominant. The gin-mezcal combo makes for an interesting and unique sour.
Guess I've gotta wait till blood oranges are back in season to make as written. Made with cara cara was excellent and refreshingly dry. With really really good blood oranges could be exceptional.