Revolution Eugene Porter Clone

I am trying to clone the Eugene Porter from Revolution Brewing in Chicago cause I love it so much (its pretty sweet).
From Revolution: "Eugene is a robust porter with 2-row as a base malt, and castle belgian specialty malts munich, caramunich and special B. The key to the deep dark color and chocolate aroma and flavor is breiss dark choc malt.
original gravity = 18.5 plato
ibus = 28
abv = 6.8%
We use magnum for a bittering hop and a bit of centennial at the end of boil."

I need help!! I know what you are about to see is slightly unusual because of amounts of specialty malts, but its pretty sweet and those help with that. Here is the recipe I have thus far.

US 2-Row Malt 9lb 0oz 60.0 %
Belgian Special B 2lb 0oz 13.3 %
UK Munich Malt 1lb 10oz 10.8 %
German CaraMunich II 1lb 6oz 9.2 %
US Dark Chocolate Malt 1lb 0oz 6.7 %


Mashing at 157 to keep sweetness up

US Magnum 16.0 % 1.00 oz 29.7 30 Min From End
US Centennial 8.5 % 1.00 oz 12.4 20 Min From End

Yeast attenuates around 70%

Thoughts?

 

just emailed them, thanks for the tip. anyone else in the meantime?

 

they said they couldnt help me out...