Picked this up at an estate sale over the weekend, and trying to figure out exactly what it is.  I can obviously tell it is a Norinco...but other than that I am hoping the experts of ARFCOM can enlighten me.  The scope mount is a BSquare, and the scope appears to be a cheap Chinese gun show special fixed 4x.

So you know it's a Norinco.
What did you want in the way of further info?
Decent rifle, of course, good condition, obviously.
If it runs consistently, and it should, you now own an economy meat grinder.
I loves me some SKS, and I'm just fine with a Chinese pinned barrel.
Only thing I'd do to it is a trigger job, and only if the stock trigger is truely bad.
http://www.kivaari.com/
Also, a return spring on the firing pin.
http://www.murraysguns.com/sksown.htm

If you're tall and long you might consider a stock extender or new longer lenght of pull stock.

Any way of telling approximate manufacture date?  What is a reasonable valuation?  Any other pictures I could provide to better assess the quality/value of this particular example?

You have a SKS that used to sell for $90 out the door and today they probably sell for $300 or more.

Yours has the 30 round mags...I hope you got the original 10 round box mag with it... if not, see if you can find one for sale just so you have it. I was never wild about the 30's with those long extensions on the front. Too bad no one ever came up with a AK style mag well adapter. Seems like it would be doable by someone with some skillz....

SKSs are plentiful and unlikely to become very valuable.
Like the above poster said, $300 ballpark sounds right.
That may double if SHTF.

Original eary USSR SKSs are the only examples I know of with collector interest.
But I could be wrong.

Norinco "commercial" type sis that has had the mag changed , bayonet removed, and a crapy scope and mount added.  In current condition at a LGS you would be looking at $500. Real value probably closer to $400.  I would not pay more than $300 for it because I'd have to invest money to take it back to its original form

It is also a PTK import.

AKA Polytech.

AIRBORNE!!!!!