I have a Norinco 56S-1 Underfolder.  Before the 56, there is a number 66 in the triangle and then immediately followed by the number "1."  What does the number "1" signify?  Is this a true pre-ban?  I've searched the internet and this site and can't come up with a definite answer.  Please assist with your comments and info.

The triangle 66 is the factory stamp. (Norinco)

The 56 is the Chinese designation for the AKM rifle. (type 56)  

Type 56-I with the -I = Copy of the AKS-47, with an under-folding steel shoulder stock and the bayonet removed to make the weapon easier to carry. As with the original Type 56, milled receivers were replaced by stamped receivers in the mid-1960s, making the Type 56-1 an equivalent to the Russian AKMS

56S the "S" = semi auto only copy for export market.

So putting it all in order = Norinco made (triangle 66) Type 56 (56) Semi-Auto (S) with Underfolder Metal Stock (-I)

Very Nice Rifle you have.

EDITED to Answer Original Question - Yes, it is a factory Pre-Ban AK

Some other interesting information on Chinese AKs.   They were patterned after the Original AK-47 (vs the AKM) since the Sino-Soviet Split hit before the AKM technology transfer was made.

The following is from Wiki on the Chinese Type 56

The Type 56 has a 1.5mm stamped receiver (like the RPK, although it lacks the reinforced trunnion of the RPK) versus the 1mm stamping of the AKM.
The barrel on the Type 56 is similar to the AK-47 and heavier than that of the AKM.
The front sights are fully enclosed, compared to the AKM and AK-47 which are partially opened.
Has the double hook disconnector of the AK-47 rather than the single hook disconnector of the AKM.
Has a smooth dust cover like the AK-47 and unlike the ribbed dust cover of the AKM.
May have a folding spike bayonet (nicknamed the "pig sticker") as opposed to the detachable knife bayonets of the AK-47 and AKM. There are three different types of spike bayonets made for Type 56 rifles. Type 56 assault rifles are the only AK-pattern assault rifles that use spike bayonets.
Military issued versions of the Type 56 lack the threaded muzzle found on the AK-47 and AKM, this means they cannot use an AKM compensator or blank-firing device. Commercial versions of the Type 56 may or may not have a threaded muzzle.
Has a blued finish like the AK-47 and unlike the AKM, which has a black oxide finish or a parkerized finish.
Has "in the white" bolt carrier, while the AKM bolt carrier is blued.
Like the AK-47, sights will only adjust to 800 metres, whereas AKM sights adjust to 1000 metres.
Nearly all Type 56's lack the side mount plate that was featured on many variations of the AK-47 and AKM.
Lacks the hammer release delay device of the AKM. The lack of hammer retarder is perhaps due to a preference of a slightly higher rate of fire, and simplicity. And did not have anything to do with thickness of the receiver, as the RPK included the hammer retarder also.
The gas relief ports are located on the gas tube like the AK-47, unlike the AKM which had the gas relief ports relocated forward to the gas block.
The fixed stock of a Type 56 has a less in-line stock like the AK-47, opposed to the AKM which has a straighter stock.

Wow, you really tried posting this in every forum, huh?



ETA: Smiley face added to avoid potential butt hurt.

The Type 56S is the fixed stock version of the Chinese AK, in semi-auto only.  The Type 56S-1 is the underfolding stock version of the same rifle.  When these rifles were banned back in 1989, Sile INC. of New York had a quantity of both Type 56S and Type 56S-1 rifles still tied up in a U.S. Customs bonded warehouse.  In order to free these rifles up so they could be sold, Sile had to basically convert them into what eventually became known as "MAK-90" rifles, although these rifles actually predate the "MAK-90" nomenclature.  In addition to bayonet lug neutering and adding a thumbhole stock, the new rules required re-naming the rifles, since "Type 56S" and "Type 56S-1" were now banned by name.  Sile accomplished this by re-stamping the affected rifles with a "1" prefix; a simple solution to the problem.  Therefore a 56S became a 1-56S, and a 56S-1 became a 1-56S-1.  

So in essence, these are not "pre-ban" rifles, as the altered model number and bayonet lug would attest to by their presence.  The stocks were very frequently changed back to the military pieces, as those parts were very available in the early to mid 1990s.  The bayonet-lugged Chinese gas block was not very common ever, and would be much more difficult to replace than a stock set.  That is why you will usually see these "1 prefix" rifles with a neutered bayonet lug and original furniture these days.  

The one caveat to the above paragraph would be if you could prove the rifle was converted back to a pistol grip configuration (non-importable "assault weapon") prior to November of 1990, when the 922r rules took effect.  Yes, for awhile it was actually legal to do this with NO U.S. PARTS; hard to believe now, I know.  If you could somehow prove that was done back then (good luck), your rifle would technically be "pre-ban".

It means that customs got a hold of it when the ban went into effect. They were supposed to modify them to post ban features before they could be sold. Some got neutered and some didnt. But the marked the with a 1 or a 7. That shows that they did "something". To a collector they are not "true" pre bans. They are the same thing in my opinion.