I'm not confusing them, I'm trying to make sure that anyone reading through this doesn't do something dumb. I have 2 grandfathered MI pistols myself, one is a M70AB1 I built myself.
In the OP's case, I'm going to guess that he got his UF AK registered and grandfathered so he can carry it as any pistol.
Anyone else trying now to get a rifle registered as a pistol is going to have two options. One, go through the SBR process then register it as a pistol. The other is to have a 16" barrel and the rest of the firearm be only 9.9". This is difficult, but not impossible, with an AK and being an UF is the most likely to fit. The 16" is measured from where the bolt face hits the barrel, which is set into the receiver a couple inches so you actually have more like 11" to play with. I believe the standard AKM receiver is around 10 1/2". Depending on the pistol grip used, that may actually be the furthest rear part of an UF AK. A side folder will have some extra trunnion sticking out the back, which will eat up length. But I'm fairly confident that it is possible, even today, to have an underfolding AK be non-SBR, 16" barrel, and still sneak in under 26" OAL folded for MI measurement and over 26" extended for the Feds.
I could be wrong. I'd measure things out myself, but I happen to be down in TN and only brought a few regular pistols with me, as the MI pistols stop being pistols at the Ohio state line. Maybe I'll remember to bust out a tape measure when I get back and update.
Thank you for all your concern that I don't know what I'm talking about though!