Interesting drink. Not a 5 star, but it intrigues me. I used olives for the first time, and it beautifully complemented the herbaceousness of the dry vermouth.
FWIW I went with my last slug of M47 for this and effing loved it, although tbf I am slightly worried I'm turning into one of those Monkey 47 cultists... been a bit of a phase.
We're soon to put live a major upgrade of our Cocktail Builder software which among other things will allow you to choose which gins in Your Ingredients you apply to each cocktail. This should eliminate this issue. I want to recommend rather than inflict my brand choices on others.