That serial looks virtually identical to my 59 letter gun....sans the XV.
Same (either A or D cyrillic letter seemingly struck at a slant) four digits slightly spaced after the letter, and lightly struck slightly slanted /26\. Mine is 5656 guns 'newer'.
The XV suffix could be refurb stamps if GM's new theory about the prefix/suffix letters on serials holds any water. With a gun this age, like my 64 with two letters, could perhaps indicate two refurbishment cycles in it's lifetime. I don't think I have ever seen either an X or a V on other suffix stamped guns, but nor have I seen M or L like on my 64. It seems like GM could be on the right track regarding what they are there for, the meaning of the letters will require further study. Location or refurb, what may have been replaced, or simply the final inspectors 'personal' stamp?
My 59 came from a batch of barreled receivers that had been stateside in that condition for decades. It's lack of letter(s) could be due to it never going through a rebuild. Going through all of my Chinese...I found that the only ones with letters also had Norinco incorporated into the import stamp. I only have two Norinco marked ones without letters, one a /906\ that came 'new' to me in cosmoline...the other a heavily scrubbed and oddest serial/arsenal stamp I have seen. It's almost enough evidence that the import stamps SHOULD
read 'Remade in China by Norinco'.
If this proves to be in the realm of true...let it be known I coined the term Norincofurb.
I would be interested in the import stamp to see if it follows along with the theory.
Nice save from the plastic on this gun, did you have to hog out any wood to allow the 20 rounder to open? I have had zero success with mine. I could only get it to fit into two guns, and neither would allow it to open enough to get any rounds out of it....which was particularly troubling since they wouldn't feed either! Both the guns it would go into, I wasn't willing to alter the stocks...so it's sitting in a drawer awaiting more SKSs to try it on. Seems like a legit excuse to buy more SKSs....right?