Overprint O. K. O. P. 10 Mk. and 15 Mk stamps - Need Country

[Pocket Change]

As scanned - Need ID

 

[Mackaydon]

[FONT=Roboto, arial, sans-serif]Bolesław I the Brave, less often known as Bolesław I the Great, was Duke of Poland from 992 to 1025, and the first King of Poland in 1025. As Boleslav IV, he was also Duke of Bohemia between 1002 and 1003.[/FONT]
[FONT=Roboto, arial, sans-serif]Another source: [/FONT]Bolesław I, byname Bolesław the Brave, Polish Bolesław Chrobry, (born 966/967—died June 17, 1025), duke (from 992) and then (from 1024) first king of Poland[FONT=Montserrat, sans-serif].
Don.....[/FONT]

 

[Mackaydon]

https://www.stamps-plus.com/results.asp?cmd=pld&searchtext=&group=10&pagenum=1
Don....

 

[Mackaydon]

Here are both your stamps:
https://www.stamps-plus.com/results.asp?cmd=pld&searchtext=&group=20&pagenum=3
Don.....