I am so excited, I finally found some Northwestern Front rubles going for a price I could afford (as they are worse than XF). These are now the rarest notes in my collection. They served as currency among the soldiers of the Northwestern Front army, an anti-Communist army headed by General Yudenich during the Russian Civil War. They circulated for only a brief time, between the 25th of August and 30th of November 1919.
1 Ruble, PS-203


10 Ruble, PS-206a


25 Ruble, PS-207a


Also, could anyone with the latest Krause Specialised Issue catalog look up the values of these notes?