I am new to AKs and have been shoping around a bit. A reputable gunstore near me has a Norinco marked NHM91. I have done a little research and found that these rifles came originaly with a thumbhole stock, am I right right? Well, this gun has a matching wood standard AK stock. The grip is wood with checkering on the sides. The rifle also has a threaded barrel with an AK 74 style brake held on with the standard front sight base push pin. What I need to know is did any NHM91s come with standard funiture and if not how can I tell if this is a legal conversion from the thunbhole to stock to a standard stock. I really like the rifle. The blueing is excellent and the wood all matches and has a nice finish. They want $565 for the rifle.

They are nice rifles, but you can find them for 350.00 to 400.00(in butthole form) for nhm90 and 91 here in Tejas. I would buy a butthole and convert it myself.

I recently passed on a NHM model becuase it had a pistol grip and the guy did not know if it was compliant with the law. I think it was $400 bucks. I know the Chinese AK are awsome but $400 can buy a good yugo

Not some,not a few but...  ALL  NHM-91 rifles were imported with thumbhole stocks. The US made parts commonly used to comply with the law are the stock,pistol grip,upper/lower handguards,trigger,sear,hammer,gas piston,and the magazine body,follower,and floor plate.
The stock set sounds like Chinese mfg. to me with the pistol grip checkered and all matching finish on the other wood parts. The hammer,trigger,sear,and gas piston if Chinese made will have no marks on them at all. If US made will have US,USA, or a C stamped on one side of them. The same with the magazine parts unmarked Chinese and marked US made.
The best thing to do is to field strip the rifle. You should be able to remove the receiver cover and look at the left side of the trigger parts and see if they are marked. Pull the bolt carrier out and see if the gas piston is marked.
If the riflle has 5 US made parts then the price is about $100 to high and if no US made parts then the price is about $150 too high.
The rifle should have a bipod attached to the barrel as all NHM-91 rifles were imported with one.

Can you remove the muzzel nut and put on  brake/flashider on a butthole stock or does it have to be all parts complyent?