You have a solid, by the numbers porter and you're pretty much squarely in the the "reasonable brewers can reasonably disagree" area of the style spectrum. I think the brown malt will determine whether or not you like the recipe--it's a bit of a polarizing malt. Many folks (like me) love it and argue that you can't make a real UK porter without brown malt, others dislike it...some passionately hate it. The trick is to understand that brown malt doesn't like to be rushed, give it a solid month (two is better) of aging to allow the flavors to come together.
Brewing minds can disagree.
Personally, I think brown malt tastes like ass. Both in my homebrew and brands such as Samuel Smith Taddy Porter. The taste simply does not work for me
You've got a pound each of brown malt AND chocolate malt. Whilst it will change the end product, one can substitute any of these for brown malt in a recipe: amber, flaked barley, chocolate, invert #3, black patent, victory, etc. (probably the coffee malt as well)
Personally, I really like the London Porter Clone found in BYO. Admittedly, BYO is an american magazine, but I like the results a lot:
5 British Ale Clone Recipes - Brew Your Own (byo.com) It is a different take on Porter with a mix of chocolate, black patent and roasted barley. As an American who first assisted in a homebrew in 1980, stereotype/style delineation is/was: American Porter is exclusively black patent (I still like Papazian's original sparrow hawk porter decades later), Stout is roasted barley and never the twain shall meet.
London Porter Clone Ingredients
9 lb. 12 oz. (4.4 kg) British 2-row pale ale malt
14 oz. (0.40 kg) crystal malt (60 °L)
7.0 oz. (0.20 kg) chocolate malt
7.0 oz. (0.20 kg) black patent malt
4.0 oz. (0.11 kg) roasted barley (500 °L)
8.5 AAU Kent Goldings hops (60 mins) (1.7 oz./48 g of 5% alpha acids)
1.25 AAU Kent Goldings hops (15 mins) (0.25 oz./7 g of 5% alpha acids)
0.25 oz. (7 g) Kent Goldings (5 mins)
0.25 oz. (7 g) Kent Goldings (0 mins)
1 tsp. Irish moss (15 mins)
Wyeast 1968 (London ESB) or White Labs WLP002 (English Ale) yeast (1.5 qt./~1.5 L yeast starter)
0.75 cups corn sugar (for priming)
Step by Step
Use moderate to highly-carbonate rich water (75–125 ppm). Mash grains for 60 minutes at 156 °F (59 °C). Collect 6.5 gallons (25 L) of wort. Boil wort for 90 minutes. Ferment at 70 °F (21 °C).
@McKnuckle I also like the WY1469 West Yorkshire (not to be confused with POF+ abomination that is WLP Yorkshire Squares. These are not the same yeast.)
I prefer Pub to WLP002. I brew a lot with vault strain WLP085, which is WLP002 and widely believed to be WLP005 or WLP006 (White Labs won't 'fes up to what makes up the blend). I will do a yeast off this winter between WLP002, Pub and WLP085.