The item was relisted on eBay and is now on RR too. I've tracked the sale of this item.
The Kalt Enforcer was updated in order to address the many problems with the original design. Improvements included new one-piece clutch, metal clutch bell, improved main gear material, new transmission case to accept a better means of retaining the transmission system and main shaft, longer tail boom, metal balls on swashplate and washout arms, longer main shaft, one-piece blade grips (original created a very dangerous situation whereby the blades would shed and destroy the heli), longer main blades, etc..... Making it a better performing heli as well as being more reliable.
Essential parts are very difficult to obtain so only a few of us fly them.
I do fly the ZR version and have put in thousands of flights since their introduction (176 logged flights this season). And admittedly, knowing the weaknesses of the the original design, have modified them to fly reasonably well.
Hope this helps,