I searched for some time and have never seen a FACTORY
KP2 DF with a long lower tube, all the ones I have seen were CONVERTED side tube KP2's.
Chad has a KP2 DF new in the box labeled as same, it has the short lower tube and a speed demon bolt. I would say it was a transition model which soon became the KP3 which then started coming with CA as an option then the PMI rifle with the later slider saftey and squared trigger guard.
here is an ad showing a KP3 with and without CA