You can say whatever faith belonged to this people? With this information it’s possible to look at the parishes of members of the Riga churches.
I found an obituary of a Janis KOZLOVSKIS, † 03.12.1939 at Riga. Burried at the Pleskod?les cementry Riga. He was a chimney sweep master (KOZLOVSKIS corresponds to the Latvian spelling for Kozlovski ending with "s" for family names of men) Can you assign this information to the wanted Jan Kozlowski?