I did this with 1 Oz of whistlepig Rye and 2 Oz of Dolin sweet Vermouth and it's absolutely phenomenal. Use a higher proof whiskey if you do this, it'll help it shine through the vermouth and balance the drink properly. I will happily make this again.
Did mine with 1.5 of Rittenhouse to kill off the bottle, but the vermouth (used Cocchi) still comes through. Curious how it would be with Peychaud's instead of Angostura.