Charles,
That 5 shilling is a nice find, that's only the second one I've seen. The small crown chips were the first issue used in the original Playboy club on Hyde Park. Since the British currency change occured in 1971 and the only casino open was the one on Hyde Park any with the old, pre decimal denominations came from there. The small crown chip denominations were 5s, 10s, L1, L5,& L25. The 10s and L1 are fairly common.

Tom