I would like to say Stables/Hamlet/Chancellor/Counting House engine, Cursing your opponent with your Ambassador. I would definitely try that, just for fun.
Open Chancellor/Ambassador and start grabbing Stables? Grab Hamlets in the Ambassador turns, you don't need more than one. You will easily have 8 Coppers from your opponent's Ambassador. You may be left behind, but will have time to recover as the double-Amb needs to build economy. Counterfeiting Spoils or even GM snowball seem like fine plans too, I don't know which one is faster. I would add Stables to any plan, though, to help connect the GMs and move past the green, since you ARE going to need some Silvers anyway, and later one you are better off discarding them to search for the GMs.