Not sure on the Country gunsmith Walter Kirsten of Magdeburg right off but I'll say he sourced his wares from Suhl or Zella-Mehlis. I would guess he was born in 1891 and expired in 1964. Following typical progression, he should have been a master by 1915 if indeed he was born in 1891 to parents Otto Kirsten & Marie Herbst Kirsten who were married in 1885 and had a brother Maurice Kirsten and a sister Helena Antoina Kirsten.

Kind Regards,

Raimey
rse