No, in fact, Jim was spot on, willy.
There is no point in discussing an act which is inherently illegal. Kinda like going to the handgun forum and talking about how easy it is to turn a 1911 into a full-auto vs. a Beretta 92. There is almost no conceivable legal means. In fact, as Jim further pointed out, if you were a Class II/III manufacturer who possibly under limited circumstances could legally alter such a gun, you would (hopefully) have much more info on the process than was available here, or at least you would be well advised to address your question specifically to such persons.
Your scenario of legally purchasing the guts of an Auto AK and putting them into a MAK-90 is far fetched, since 90+% of a Full-Auto AK's price is the FULL AUTOness... IOW, if you canbuy Class III, then buy class III. The situation is a littel different with HKs and ARs, but with AKs I feel safe saying that your scenario if far-fetched at best.
Even if you were talking about an AR.. your question might go like this:
"I want to build an AR from parts, I have been told that certain bolts are incapable of being used with FA parts. My friend has two bolts, I want to be sure that I get the convertable one if I can, as an investment."
That question could be innocent, or it could be a precursor to an illegal act. There is no way for us to know. The TFL FA area has never existed to pass along information that would make illegally converting a weapon easy.
Now, getting back to your question:
At some point in the early 90's I believe there was a shipment of MAKs into this country that were "missed" at the customs check point. Although these guns were SEMI-AUTO ONLY, they featured a reciever which would accept AK full auto parts. These parts are readily available at many gun shows (supposedly as replacements for existing LEGAL FA's). The ATF went about trying to track down these MAKs and return them to China. I believe that they were highly successful in recovering most of these guns. I am not sure of the legal issues surrounding ownership of one of these easily convertable firearms is. To my knowledge, a good many of them were transferred as "normal" MAKs. It seems like there was a serial # list of the weapons in question, though I have never seen it.
IF you did own one of these guns, my impression is that it would be legal, so long as you did not also own the FA drop in parts that could easily make it FA. As we all know, the ATF considers having all the parts the same as having the completed weapon.
If you really are considering "investing" in an easily convertable firearm, I suggest you consider the realities:
Option 1: All FA becomes legal. (yeah right, as if). In this case, your gun isn't worth much more than any other gun, which with a little attention from a drill press and/or dremel tool can also be made FA.
Option 2: All guns become illegal and you try to sell your easily convertable MAK on the underground: Oops, that guy you were trying to talk into buying your illegal gun is actually an undercover ATF agent.. sorry.
Option 3: You buy this gun and then get tempted by small demons living in your head to "just try it out"... you buy the parts, you drop them in, you head out into the back yard--Whackka-whackka-whackka-whackka-- Wooooooooo-woooooo-woooooooooo--"DROP THE WEAPON...STEP AWAY...PUT YOUR HANDS ON YOUR HEAD... etc, etc...."
I advise you to either get a legal Class III or not concern yourself with the definitely 100% illegal area of weapons conversions.
[This message has been edited by Rob (edited July 24, 1999).]