You can get Branston Pickle in the US! On a whim, I checked out the local World Market, and lo and behold, there it was, complete with a glowing Jesus-esque halo! Naturally, I snatched it up, and the next time I make a grilled cheese sandwich, I will slather it in Branston Pickle.
In response to the OP - yes, I did buy it because of repeated references to its divinity by Mr. Yahtzee. Whether or not it actually contains Love, hope, happiness, Jesus, and heroin remains to be seen; I will keep you posted!