I've heard these rifle called "Transistion" guns. Fitting, becuase they are the ones imported in between the '90 and '94 bans.
IIRC these guns will have some of the postban features, but not all. The MAK 90 was affected by the first importation ban of '90 (I think?) This was an importation ban affecting mainly the imported weapons and which limited the number of "evil features" to one in addition to the detatchable magazine. So we ended up with the MAK 90 designation, detatchable mags, thumbhole stock, no bayonet lug, and a threaded barrel with a muzzle break.
Then in 94 they clamped down and we ended up with the neutered versions we can buy now. Basically no threaded muzzles and pistol gips allowed only if there are a certain number of US made parts on board.
I have a MAK 90 "Transistion" pre-ban rifle. Fun gun, but not as good as I thought it should be. It has a threaded muzzle, muzzle break (not permanently attatched), thumbhole stock, detatchable magazine, and no baynet lug. I know this particular rifle to be legal or at least I have an extrememly good defense if challenged otherwise - I bought it from a sherrif's auction. It had been seized as part of a cache of weapons, some FA illegal and other fine. They were all shipped off to the BATF by the SO and the illegal configurations were destroyed (or whatever the BATF does with converted AKs and FALs) After the case was disposed, the BATF returned the guns to the SO for disposal and, wonders!, the SO held the auction after asking the BATF if they could do so and if everything was legal. Of course all of this was documented and public record so when I picked up the MAK 90 I got my documentation.... The box the MAK 90 came in even had a BATF case number in magic marker on it and evidence tags inside with the old information still in place.