Excellent report GM.
Having seen the models you made for the BRAS and MAMMARIES, I'm looking forward to seening more of your stuff in the future.
Might think about giving the BRAS some form of save

. Its a pitty they fluffed their attack rolls with the explosive lances - it would have been interesting to see what effect the had on the steam tank and how that affected the balance of the game.
EDIT - Thinking about the short-lived BRAS in the battle, I think they actually performed an important role. Their size prevented the steam tank from firing on the advancing naval transport walker and, once they contacted the tank, they distracted that the Prussian troops on guard so that the troops fired on the BRAS instead of on the advancing walker. This ensured that the walker arrived at the objective in one piece and was able to disgorge its cargo of matelots. If the walker had taken a serious hit earlier in the game the result could well have been different.