Concur. Rifle is a "K" series, the last built that we know of. It is a refurb, you can tell by the stock. A Tula arsenal gun, appears to be in fair shape. What did you get it for OTD, if you are willing to say?
Question: What is a Letter Series? The Letter series were some of the last SKS to come out of the Tula Arsenal. They were manufactured in '55/'56 and the "D" series is the first that is generally known about. There are "I" and "K" series. Several of all three are among the ownership of board members. Condition can vary widely from really beat up examples to the pristine (which are somewhat rare). The rifles can have exchanged stocks (refurbs) or stocks, generally laminated, that were original to the rifle. An all matching Letter Series in unrefurbed pristine condition can be quite expensive if you get into a bidding war on GunBroker.
More seem to be showing up lately and four have sold on GunBroker in December from $370 to $475, all being refurbished rifles.