Here's the problem I see with those ingredients - you lack a sweetener. Solerno is not sweet and is pretty light in flavor, Averna is a MONSTER of an Amaro.....and orange bitters will get drowned by Averna completely.
Here's what I'd do, if I were you:
Angostura, NOT Orange Bitters
Stir with ice, strain, serve over one big cube in a chilled glass
Garnish - 1/4 of an entire lemon's peel....go BIG on garnish to help fight the Averna trying to take over.
I bet that'll be rad.
Please report back, I'm putting $100 on black on this one.