Good eyes GG, I was trying to decipher as I was leaving work, but the faint characters and numbers just weren't coming together for me at all.
The arsenal stamp looks like this when struck well Al:
The "type 56" marking in Chinese characters looks pretty much the same on most carbines, but there are some that are a bit funky.
This one would be the standard:
五六式but much of it is obliterated or was very poorly stamped.
That PU style scope mount is a Kengs specialty, not really seen on many other imports (except maybe AAI out of Kansas City...there may be more but that's all I can remember off the top of my head). The glass bedded stock was probably done stateside by someone who wanted to try (and likely failed) to get sub 1 MOA accuracy out of your typical stock SKS. Nice carbine, how's she shoot?