So, due to my recent purchase of an as new SKS and stumbling in here for answers ... I am now a junkie about IDing my SKSes. The first one I picked, also Chinese, and the one my daughter loves to shoot and calls "Fried Rice" is in good to VG condition and hass a Triangle 206 designation. It has one of those tiny B-West import marks that says: Made in China by Norinco 7.62 x 39 Sporter B-West TUC. Everything SNed on the gun is 13850 except the reciever, which after the "56" chines characters gives a 1969 # with a suffix: 1415532 BE. What do the suffixes indicate? Phase of the moon? This gun has no marks anywhere signifying arsenal refurbishing. Given the condition of the stock, which is VG, I doubt it every saw combat.
Probably importer's mark. Posting a pic of the area will get you the answer you require. :)
We been seeing these random letters on chinese guns for ever now and there is still no real answer as to what they indicate or who put them there. Personally, I think it was the exporter in china.