Ramiro and Norma,
A good place to do the kind of analysis that is necessary to determine the "effective" hydration of November's dough is the Nutritiondata.self.com website at
http://nutritiondata.self.com/. If you look at the Nutrition Facts for evaporated milk (I did not see a 2% version), cider vinegar, brown sugar (light or brown) and unsalted butter, and do some simple calculations, you will see that the above ingredients have the following percents of water:
Evaporated milk: about 72.8% water
Cider vinegar: about 92% water
Brown sugar: about 1.4% water
Unsalted butter: about 17.9%
Applying those percents to the amounts of those ingredients in November's dough formulation, I get a water contribution from those ingredients of 75.462 grams. Adding that amount to 84 grams of water, and dividing that quantity by 288 grams (144 grams + 144 grams), the "effective" hydration is about 55.4%. The dough might feel a bit wetter if we take into account the effects of the fats in the unsalted butter and the fat content of the evaporated milk.
I will leave to you how best to increase the total effective hydration if a higher value is desired.
Peter