Playboy London opened using two different racks of chips.
The other set were made by TR King (California) and sold to Playboy by Dolmat (London) Ltd, another distributor.
They were supplied to the Playboy London office as the casino was not yet ready.
Both distributors only supplied that single order. All future orders were via distributor John Huxley (London)

I don't believe Sullivan ever owned any mold.

Based on many similar I've seen in the past I think the dice are samples.