Hello,
This 10kop stamp is giving me hard time, any help leading to the right identification would be great. The stamp condition is very poor, the cancel is not of any help unfortunately, perf is 14 1/2 : 14 3/4-15, I think it has wm but I'm not sure and it looks to me that it's vertically laid paper. Thank you


With wm liquid

Applying uv light