Old Ale recipe (from scratch)

I am trying to do an old ale from scratch after reading about some of the characteristics and common ingredients for an old ale. So far I have come up with this as my recipe:

Pale ale 3.5L. (9.9 lbs)
Crystal malt 120L (1.25 lbs)
Crystal Malt 60L. (4 oz)
Chocolate Malt 350L. (2 oz)
Northern brewer hops (1.25 oz) 60 min.
Challenger hops (.25 oz) 30 min.
Challenger hops (.25 oz) 15 min.
Challenger hops (.25 oz) 5 min.
White Labs Nottingham Ale Yeast WLP039




Any thoughts on this as a recipe? Suggested changes?

Oh I forgot to mention it's a 5.5 gallon batch from a 7 gallon boil.

Hey man I can't say whether that is going to be a good recipe or not, it looks really good to me, but I am in the same boat, wanted to brew an old and wasn't sure how to formulate the recipe. If you brew this let us know how it turns out