Simon Rumley is a pretty cool and headstrong director, but even though he isn't quite bound to a single genre, I didn't really see him doing a typical British crime flick. The genre is one of the pillars of British cinema and has enough stretch for directors to show their worth, but somehow Rumley's more psychological and individualistic style didn't feel like an immediate match.
What surprised me the most though was that so little of his typical elements survived in Once Upon a Time in London. It's really just a bog-standard crime flick that details the rivalry between an established crime boss and the new guy on the rise. No doubt you've seen this a hundred time before.
Performances are decent and there are a couple of memorable scenes, but overall the film lacks stand-out moments and the direction simply feels a bit flat and uninspired. It's not a terrible film and it's decent filler, but I wouldn't be surprised if Rumley was simple doing this to keep busy, until he can find/fund another project closer to his heart.