Southern Brown Ale

I had my first Brown Ale on a flight to London 20+ years ago and I loved it. After thinking about it for a long time, I think it might have been Mann’s Brown Ale. I would like to recreate the recipe, but I don’t think many of the books do it justice. I have often brewed the Northern, nut brown style and even won a medal or two with it, but I want to recreate that first brown that I enjoyed so much. I am also planning on entering it into a local competition so I am going a little higher on the gravity. How does this recipe look for a 10-11 gallon batch at 1.040? I get average-good efficiency.

12 Lbs Maris Otter (I do have a bag of Golden Promise too.)
1/2 Lb Crystal 50/60 (Baird’s)
1/2 Lb Crystal 135 (Baird’s)
1/2 Lb Crystal 150 (Munton’s)
1/2 Lb torified wheat (Briess)
1/2 Lb Victory malt (Briess)
1/4 Lb Chocolate malt (don’t remember)
15 IBU of EK Goldings or Fuggle
London type carbonate water
I plan on splitting this between 3 carboys with different yeasts: WY 1728 Scottish, WY 1968 London ESB, and WY1469 West Yorkshire.

I am kind of avoiding sugar, other than priming sugar, so I don’t have bottle bombs. I have thought about using some Belgian D1 or D2 syrup though.