Vintage Russian RPK Sliding button automatic knife

Vintage Russian RPK (Russian Prison Knife) switchblade. These knives were made by inmates of Russian prisons back in the 1960s and 70s to be sold to raise capital for the prisons. They are all hand made and very unique and beautiful pieces of Russian cutlery Folk Art. This knife measures 22cm (8.75 inches) open with a steel frame and carbon steel blade. I believe the blade to be nearly full and it has been lightly sharpened. The knife works well with the blade tip seating deep in the well when closed, smooth snap (not strong, but opens fully) and good lockup when open. The blade is activated by sliding the button down toward the bottom (back) of the knife. I'm not sure what the scale (handle) material is, but nice black & white (tuxedo) in very good condition. Very cool vintage Russian RPK switchblade.