Who makes these chips?

[Colquhoun]

They are called "King's Casino" and are pictured here or here.
They look like the RT Plastics chips but are not, and I would like to get a set without denominations. There are not to be confused with some cheap plastic imitations that I found on eBay. Any idea who makes these chips? If you have handled these chips, how would you compare the feel and sound to some better known manufacturers' chips? Thanks!