Right in the middle of the ghost range...so late 56 early 57?
^ This
https://sks-files.com/index.php?topic=360.0Early to mid 1956: Soviet Sino Guns, S/N 0001 to ~2000.
1956 – to at latest, April 1957: Ghost Guns, S/N ~2000 to ~213,700.Early 1957: six digit /26\ marked guns, S/N ~213,700 to at least 348,996.
Late 1957: 2 million /26\ marked guns, S/N ~2,350,000 to at least 2,441,000.
1958: 3 million /26\ marked guns, S/N ~3,000,001 to at least 3,233,000. First observation of the stock side sling swivel.
1959: Letter Prefix /26\ marked guns. Stocks contain narrow font.
1960?: Letter Prefix /26\ marked guns. Stocks contain wide font. First observation of large (1/4” tall x ~1/4” wide) font. These guns could theoretically be lumped with the 1959 letters, and 1960 could have been a very light Type 56 year. There is really no hard evidence pointing one way or the other, though I would lean towards major disruptions in Chinese Type 56 production as the Sino-Soviet split was entering full swing and China could no longer rely on easily getting barreled receivers supplied from the USSR. This also can give additional meaning to the Chinese ideograph markings seen on the 1961 built carbines as they were now fully Chinese built.
1961: 6 million /26\ marked guns, S/N ~6,000,001 to at least 6,021,000. First observation of the 五六式 stamp.
1962: 7 million /26\ marked guns, S/N ~7,000,001 to at least 7,170,000.
1963: 8 million /26\ marked guns, S/N ~8,000,001 to at least 8,209,000.
1964: 9 million /26\ marked guns, S/N ~9,000,001 to at least 9,218,000. First observation of short barrel lug, first observation of spike bayonet.
1965: 10 million /26\ marked guns, S/N ~10,000,001 to at least 10,442,000. Stock sling swivel relocated to bottom again.