Just been reading up about your Tonkinese as I can`t say I have ever actually even seen one apparently there is a small dedicated group of breeders in Australia
Some real glowing reports about them on the net especially like the "hybrid vigour" aspect of them
From the net "As the Tonkinese is a product of two separate breeds, they show improved hybrid vigour. Tonkinese are less likely to suffer any genetically related conditions which may be associated with their parent breeds. Influence of this hybrid vigour will become less apparent as pure Tonkinese continue to be bred.
The blend of Burmese and Siamese resulted in a type which displayed obvious, but more refined characteristics of each."