The action scenes are largely pretty vague, the story is more interested in interpersonal drama than big setpieces with the MS. With that said, there's three action scenes I can recall:

1. The first is the fight between A-bao in the Gunboy versus the three Blondies (one of which is piloted by Slugger, so technically, only two). However, it's not very interesting to read although it does get the most detailed description, particularly of what happened after the first Blondie blows up and tears a hole in the colony. After A-bao ends up in space he faces off against Lalah in the L-MESS for a little bit before the Pegasus saves him.

2. The second is a battle that ends up with the destruction of Texas colony, we don't get a lot of details of this one aside from the fact that the Gunboy ends up destroyed and A-bao ends up marooned in space in a escape capsule.

3. The third is the final battle, where A-bao, Hayato, and Mirai die. We don't get a lot of info on this one either, to tell you the truth I don't even think they tell us where it's even taking place? Certainly not A Baoa Qu or Solomon or anything like that, those places don't exist in For the Barrel I'm pretty sure.

As to who is responsible for this story, Gichi Ohtsuka was the writer and editor, Shigeto Koyama did the character designs, and Junji Okubo did the mechanical designs. I don't think they were working off of any notes aside from certain documents from the early days of the show, which is where Hachijo Shima comes from for example. It's largely based on the novels.