Malay Peninsula coins

I have acquired a small set of Malay Peninsula coins.
Metal ..... :Tin/copper?
Weight... : 0,2 to 1,0 g
Diameter: 13 to 20 mm
Reverse  : Blank
I was hopping to identify them through Nunista pages but it seems it is more difficult than I expected.
I do not even know if they are up-side-down...
Can some one help?

Usei este link que me deu algumas pistas mas insufucientes:
http://www.fsrcoin.com/palembang.html

Did you try Zeno?
https://www.zeno.ru/search.php?searchid=362349

Hello, I bought some of those last week.
I recognise some pitis of Palembang in your set.

N°6 : https://fr.numista.com/catalogue/pieces85525.html
N°9 : https://fr.numista.com/catalogue/pieces86585.html (?)