That long head tube, machined seat tube, and wishbone rear triangle speak of something special there. I don't know if Kona or its predecessor BDG (bicycle Design Group) ever did wishbone rear ends. In all honesty, I don't know what that may be but it doesn't fit the typical cookie cutter MTB mold. I would guess late 80's - early 90's just based on the rear U-brake/rollercam mounts. I had a Nishiki in 92 that came with Deore LX. If you decide against keeping the frame I'd be interested in taking it off your hands.