Thanks guys.

I'm afraid I don't have any stamps from Yili and only a handful from the whole North-West China area.
SG lists 14 stamps from Yili.
The first 10 were handstamped diamond overprints on Sinkiang stamps that were themselves Chinese Sun-Yat Sen stamps with overprints. These were issued in AUgust 1945.
This stamp is one of four in different designs printed from woodblocks all in a deep violet colour. These were issued in February 1949.
This one is the $50.
There is a horizontal $100 stamp but I can't work out what the design is supposed to be. SG doesn't attempt to describe any of these designs.
There is a vertical $200 stamps showing someone on a bicycle.
Finally, there is a horizontal $500 stamp which I think shows miners working.
These stamps reflect what to me is a pretty obscure bit of history.
SG says that in 1945 the Uygur inhabitants of the Yili valley in N.W. Xinjiang on the border with Kazakhstan declared their independence of China and issued stamps.
SG goes on to say that the Yili Republic joined the Chinese People's Republic at the end of 1949.
Here's a rather different perspective from Wikipedia which puts this in the context of a Soviet-inspired revolt against the (Kuomintang) Chinese Republic.
(I suspect that the "Yili Republic" and "East Turkestan Republic" refer to the same thing.)
https://en.wikipedia.org/wiki/Secon...tan_Republichttps://en.wikipedia.org/wiki/Ili_Rebellion