thought they came from German, polte plant，but Germany headstamp usually have a “*” after the letter s.
Also wonder which year were they produced，any info pls
Polte indeed, made in 1911 and 1912. The other number ist the month.
Letter S shows these cases have the neck dimensions for the S-Geschoss adopted in 1903.
The asterisk (S*) you mention was introduced much later to indicate the return to brass with 72 percent copper long after WW1.
By the way, China used the same caliber designation as the German army: 7.9 mm for this cartridge.
The number 7.92 is a Czechoslovak invention from after 1918.
Thanks for the comprehensive answer.They might be imported for advanced m1888 and gew98 at that time.