I don't wish to spoil Richard's post as I don't like to take over other people's posts (unlike some others) so I will put it here as it finishes it off.

"For Tom to mention the £100,000 "plaques" in his book and the exact process how they became, he had to have got the information from someone who knew what they were talking about; either Victor or someone very close to Victor... and there could be very good reason why nothing else is known (mentioned); especially if only used on a private game and in a private room where nobody else would know they existed -- except the manufacturer... and I think there were exactly 10 pieces of the £100,000 made and not 11, as with other very low productions where one piece was kept in shop."

The information about how the plaque was made and its existence did indeed come from Victor but not personally as implied, it was taken from Victor's book and I'm more than happy to accept/believe it now I know where the information came from as opposed to what sounded like pure speculation with no other details offered. Maybe Tom got the information about the other unknown denominations from Victor or somebody that knows more than we do.
The value was set in diamonds it seems.
We now know that, even though the thread was only about Playboy, you were on about totally different plaques all together which was impossible to fathom from that sentence.

"maybe Gaming didn't know about both the gold metal plaque and the plastic £100,000 plaques Tom refers to... and thus no record of them along with the £10,000 plaques Tom mentions and, mayhe whomever informed Tom of them had a reason to."

Of course, the gaming board knew about the plaques as would some of the staff (although none that I have spoken to) although obviously a long time has passed since the Playboy opened and many of the original staff have since passed on but at least I tried. I hope to find somebody that actually remembers £100,000 plaques but that may never happen.

According to the same book, Crockfords made plaques for Playboy too although only the chips have surfaced so far. I wonder if they will ever turn up or maybe they already have somewhere.
It still raises some questions but at least the 2 statements that weren't strictly correct (or possibly held back details just to create doubts) have been answered now.
Now we just have to find the Crockfords made plaques along with filling in some of the other gaps in the chips.