Where is Gaston?

[BigJamal]

I gave a cigarette to Gaston when I found him to get the Mustang-11, but when I reached the Observation Tower, I couldn't find him. Can anyone help me? I'm trying to unlock the American Horsepower Challenge.

[BubbrickDuck]

In chapter 2, you find Gaston in both the area below the artillery cannons, and in the area with all the other French soldiers behind the locked door
In chapter 3, he will be in fort saint Michael past the fire
In chapter 4 (when you go back to the trench), he’ll be in the sleeping quarters on the far right
In chapter 5, it’s kinda hard to explain but he’s near the giant rubble that you shoot with an artillery cannon
In chapter 6, he’s in the observation tower
I would probably just look at the 100% competition guide instead since he explains it much better and shows you where exactly Gaston is throughout each chapter

[Lanzagranadas]

There are five times you can find him and give him a cig. I luckily didn't miss any and got his handgun in chapter 6, so no idea what's supposed to happen if you missed any of them, whether he's not meant to be at the tower at all, or he is meant to be there but not give you the gun. If it's the later you've run into a bug.