I've got a "London Pride" clone lined up too. I do knock out slightly larger quantities, but a comparison is easy - I just shift the decimal place back a notch. My hop schedule was taken off the Fuller's Web site too, but also an interview with the Brewer found here:
http://www.thebrewingnetwork.com/post1621/ and Part 2 is:
http://www.thebrewingnetwork.com/post1633/.
I think the main difference is you are using 15 minute additions whereas Fullers get virtually all the bittering from the Targets and the rest go in the "whirlpool" (or I give them 2 minutes). And they have a few Golding floating about. So my schedule is (bear in mind this to serve as cask and you need to bump it up 5-10% for bottles):
Target (11% AA): 3.9g 60mins
Northdown (8.5% AA): 1.3g 2mins
Challenger (7.5% AA): 1.3g 2mins
East Kent Goldings (5.9% AA): 1.6g 30min steep
I've also got EKG down as dry hops. Two batches of 1.5g, one in fermenter, one in secondary. Have them in bags so they can be removed after 4-5 days.
A concern you hear a lot is "does the hop schedule need upping". NO! You are brewing a traditional English bitter, not a new fangled American Pale Ale with exotic hops. And 33IBUs (30 for cask) is top end for English bitters/pale-ales.