I think that these were the last plaques issued with Le Cercle Les Ambassadeurs on them as the next ones I know of don't have Le Cercle on.
Made in March 1978 and in limited numbers (check the chip guide for more details).
I think that the metal token replaced the original £500 plaques but could be mistaken, it just makes sense. I thought there were only a small amount made but have since seen one numbered in the 400s.

Backs have the building on again.

Token. I have seen another made in the same LGK style (Sportsman) but it wasn't a £500 and had no value on it.

There was a 1974 set (£50 and £100) that I assume were made to bolster up the numbers of the earlier ones and make them both up to 400 in total but, again, not 100% sure (it just makes sense). They are smaller and smell totally different (as do the last 1978 ones).

The £5,000 and £10,000 plaques are the only other ones that I have but I know there were other higher values in the 1978 set. Not sure when the £5k and £10k that I have were made but they are pretty impressive.

I hope it was interesting to see almost the complete (known) stock of gaming "tokens" from a high-end London casino as it's not something that happens often.

There is also an "odd" set of jetons that I think was seen in the Roger Moore film "The man who haunted himself" but I am still researching those.