imported post
You still haven't answered if your gun has sufficient US made parts to be legal in the configuration you are offering it.
The following is a list of parts that the ATF considers imported parts for semi auto rifles and shotguns. Please note NOT ALL OF THEM are found on all rifles. This list specifically references which are SKS specific parts, and then references which are readily replaceable with US made parts. Your SKS has 17 imported parts, of which 7 must be replaced with US parts in order to be legal. Look at the list and for every item marked as being an SKS part, check to see if yours is marked USA. IF YOU DO NOT HAVE ENOUGH US PARTS in order to be legal with your collapsible stock REMOVE IT IMMEDIATLY AND RESTORE THE GUN TO IT'S ORGINAL MILITARY CONFIGURATION. DO NOT OFFER THAT GUN FOR SALE IN THE COLLAPSIBLE STOCK IF IT LACKS THE CORRECT NUMBER OF US MADE PARTS! YOU WILL BE COMMITTING A CRIME.
1. Barrels (US available, not worth it)
2. Receivers
3. Muzzle attachments (exists only on Yugo M59/66, US made available)
4. Barrel extensions (doesn't exist on SKS)
5. Bolts
6. Bolt carriers
7. Gas pistons (US available at Tapco
8. Operating rods (This is the secondary piston, US available at Tapco)
9. Trunions (doesn't exist on SKS)
10. Triggers
11. Trigger housings
12. Sears
13. Disconnectors
14. Hammers
15. Buttstocks (Variety of Polymer US stocks available)
16. Pistol grips (not originally on SKS, but integrated to US made folders)
17. Handguards (US available with stocks)
18. Magazine bodies (US available)
19. Magazine floorplates (US available)
20. Magazine followers (US available)
Out of 16 parts (or 17 for M59/66 Yugo), there are just enough US made replacement parts to bring the count down to 10 or less.
Original source for list here...
http://www.gunandgame.com/forums/sks/24939-sticky-submission-sks-legalities-what-you-can-change-what-takes.html