Hi, monkey, and WELCOME ABOARD!!!!
The gun is a Norinco. The left side fo the receiver reads like this.. /306\ (3 Chinese characters) 1814XXX J
Then it says SKS 7.62X39 MADE IN CHINA BY NORINCO POLY USA ATL GA
It was made in factory 306, and I have no idea where it is any closer than "somewhere in China." The second set of markings are the importers marks, placed there by the company that brought it into the country. I'm not sure who "Poly" is, but they are/were located in Atlanta, Georgia at the time of importation.
The gun is in a black composite stock, came with a spike bayonet and od sling. All the serial numbers I have found match.
Sounds like you have a nice original rifle that the previous owner has mounted in a poly stock. It's unfortunate that it's not in it's original wood but there are Chinese fiberglass and wood stocks available so if you want to put it back into "original" condition, less matching s/n on the stock, it shouldn't be too hard to do.
the gun is in 90-95% condition, very nice. What do you suppose it is worth?
A lot depends on where you are (which is one of the reasons why there is a location slot in the profile) but I'd guess that an average retail price would be somewhere in the $200 area.