The corruption described is almost entirely contained within the area of high finance; it's not a very corrupt country from the perspective of the average John Bull. It is however quite deferential, which means that power and prestige let you get away with things.
Have to add that in truly corrupt societies the degree of power circles corruption is not any lower. It just looks less appalling from corrupt baseline.
The 'old boy' network that powers the country is not contained within high-finance. It is just tightly linked to through wealth management and lobbying.
I was invovled a couple of times in bidding for the government contracts. Do not have proofs, of course, but the entire design of this system was very open for corruption.