you can find sks rifle at virtually any gun shop but searching for a Chinese version may be a little more difficult.
Some of the later rifles and shotguns have been imported. Most appear to be made in the US.
$200 - $300 for a basic Type 56. Even though importation has ceased, they're not particularly rare (especially as NORINCO is still manufacturing them) and don't have the collector value of other SKS rifles. As for the year, NORINCO doesn't publish SN data. If it's in the US, then it would've been imported no later than 1993.
US Army long arms (rifles/muskets) were Made In The USA. Confederate States of America (CSA) long arms were primarily IMPORTED (from England/France).
NORIS appears to have been a firearms manufacturer in Spain who imported shotguns and rifles into the US during the 1960s.
The SKS and AK-47 saw their "FIRST" full scale action against US Forces during the Vietnam War; 1961 thru 1973. In Vietnam, SKS's were replaced by the AK-47 by 1969. If the SKS was built prior to 1973 and has a US Government tag accompanying it as a "War Souvenir" then it is a "battlefield pick-up." All GI's bringing SKS rifles or K-54 pistols back from Vietnam had to have a tag on them. AK-47's could NOT be brought home as war souvenirs. Since the Vietnam War, the SKS's, AK-47's, etc. have been used by nearly every nation on earth and are common in the US. If the SKS in question is not a "Viet War Souvenir" then it will be difficult to trace it's combat history.
There were many firearms factories furnishing arms for both sides in the US Civil War. Colt, Remington, and Starr manufactured the vast majority of the Union's revolvers. The Springfield Armory made most of their rifles and muskets. The South had several small manufacturers and imported many arms from France and Belgium. The South also imported arms from England.
Firearms imported before the implementation of 922r are grandfathered in, yes. However, 922r went into effect in 1989 - not 1994, as so many people like to believe. Be aware of this before you assume you have a pre-922r rifle.
$375-$550, depending on condition. Rifles were actually made in Yugoslavia, imported into the US by Interarms.
Nationalist China (Taiwan) used US supplied weapons. Red China used Soviet type weapons and SUPPLIED many of those to North Vietnam...such as the MiG-19 (J6 CHICOM version) jet fighter. AK-47 assault rifles, SKS semi-automatic rifles, K-54 pistols, etc.
alot
It was round about 500,000