With the current anti-gun, especially anti-semi-auto feelings I doubt if you'll ever see Chinese semi-autos imported again. And, although Clinton was largely responsible for the so-called "Assault Weapons Ban", it was George H.W. Bush that stopped importation of Chinese semi-autos by executive order.
As I indicated earlier, I like these rifles and own several. I can see by your photos that your specimen is better finished than most, with a better polish and blue, and a nicer stock. I own a couple just like yours. They were made for possible military issue, either for the Chinese militias or as foreign military aid, and are noticeably nicer than the NIB $89 rifles that came in the box with blond finish stocks. At one time I had quite a variety of these rifles in my shop for sale, and was able to closely examine the differences, so I assure you that what you've got is better than the more common one. I even had some very, very used specimens that looked like they had all the finish sandblasted away and then soaked in crank case oil. I got tired of looking at one that just sat there and wouldn't find a new owner, so I remodeled it into a sporter. The only good things that it had going for it prior to remodeling was a very nice chrome bore and a screw-in barrel. It is a NORINCO. I'm not a big guy, but you're correct about the length of pull problem for us occidentals. I've seen several solutions including gluing on a piece of wood to lengthen the stock, but it's always noticeable, and you loose the buttstock storage capability. The slip on rubber extension pad is the best and most common solution for those unable to adapt to the short stock.
Attachment 247515Attachment 247516
Click to enlarge.
As for acquiring a MAC-90 -- I had one of those also. They weren't on the market as long as the SKS was, cost a bit more to begin with, and you're correct that the prices on them have gone through the roof. But again, opinion only, even at the time they weren't the best AK-type carbine available, and had that weird thumbhole stock made to get around the Assault Weapons Ban prohibition of a pistol grip. I sold mine for twice what I paid for it and was happy to see it go. I replaced it with a Romanian version, a cheapie as AKs go, just for a gunsmithing specimen to have in my shop to refer to if an AK should come in for repair. One never did -- AKs are very stout. The Assault Weapons Ban passed away, as it should have, but quite a home grown AK industry developed to circumvent it and the Bush import ban, and were it me I'd look to something made here in the U.S. as likely being of better initial quality and a warranty easier to collect on. I'll kind of bet, though, that when you eventually acquire an AK of some sort you'll come to agree that the SKS is more of a rifle, great for all the things rifles are great for, and that the AK is great for spraying lots of lead but much less fun for serious target practice or hunting.
DG