Any time we deal with e-bay, a
pound of salt is in order!
But in this case, I have no great objections to the description. It does look like a lot of home-made knives in 1970s Russia. At that time, EVERY bladed weapon was banned ( not just "slap-on-the-wrist"- banned, but " you-go-to-jail"-banned !!!

) To purchase a hunting knife in a sporting goods store one had to bring an official permit from the police, register the knife and pay yearly tax ( just like machine guns in the US). Obviously, all hunters ( and criminals, and everybody else

...) had illegal,fighting style home-made knives. Something people should remember when they discuss gun control...
This one looks very much in line. Its style reminds old Russian-Varangian swords: national pride at its best! As to its alleged prison origin... Also may be true: I have a Russian book on prison knives: they made gorgeous and supersophisticated stuff in the GULAGs! Kind of underground art therapy
So, my friend, it all may be absolutely true!
Still.... keep the grain of salt...