Identification of token/coin ? [solved]

I need help for identifying this coin/token. Diameter is 27,6 mm, weight 4,15 gram, composition bullion?

Thank you in advance

Kind regards

Krax59

This is a Ga-Den Tangka from Tibet. 

Here's a detailed article about them. There are many varieties. 

From the weight and the photos you may be able to identify the variety of your example.  

Thank you very much for helping and the copy of OCCASIONAL PAPER NO.17, THE GADEN TANGKA OF TIBET by N.G.RHODES . The Coin is Class F tangka 1918-1922 (xi).