Glad you like it. Please copy away, as it is all made from Sally 4th products that are available now, I'm looking forward to seeing lots of copies and probably improvements over the next few months.
The terrain has been built on Terra-Formers. These are terrain foundations made from boxes that are 12" square, with laser cut profiles so that every terrain feature matches up exactly between boards and so that all corners are exactly 90 degrees. The boards come with strong rare earth magnets to hold them together in use. You then build your terrain inside the frame, knowing that everything is going to line up nicely.
The bunker tile has been designed so that interiors can be made that can be rearranged so that every game is different. Each bunker tile takes 25 Terra-Block interior tiles (50mm square). We have designed it so that 4 Bunkers can be filled by our Terra-Block Starter & Deluxe Starter set.
If you missed it, their was a detailed review last weekend by the Beasts of War Weekender team:
https://youtu.be/EHvPljX1CPQ?t=1h33m01s