I really don't know what the Munton's yeast can do, but I expect you've taken it about as far as it can go. You did get 66% apparent attenuation, so you shouldn't expect much more from your typical ale yeast in a big beer like this. You can try rousing to see what happens, but you are probably pushing the alcohol threshhold. If that's the case, you can add a pound of sugar, and you still won't get carbonation. What was your target FG, anyhow?
You probably need a more alcohol tolerant yeast to attenuate your beer any more, and that includes for carbonation. After you pitch, though, you better get it fully attenuated, or youwill risk bottle bombs.
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