I was under the impression that around 1956 was when pretty much the last of the Russian SKS. What you're dealing with is almost certainly a Romanian clone, not a Russian SKS.
The format of that serial number suggests it's Romanian, it is not consistent with the format of the serial numbers used on the Russian rifles but fits perfectly the Romanian pattern.
What's more, the character "R" (not be mistaken for "я") does not exist in the Russian alphabet.
Another thing is the triangle (even with an arrow in it) is also a Romanian arsenal mark, it looks a lot like the Russia's Izhevsk Arsenal, but it isn't.
Lastly, Romania was still producing the SKS in 1960, Russia was not.