Hoback Kwaiback LE vs UHEP vs MK? vs Custom

[gatorforge]

So I relatively recently I picked up a Hoback Kwaiback Limited Edition 70. Great knife, but as I started looking into it, I can't seem to make out what model is what and where this fits into the line up. Everything I'm seeing now is marked UHEP or MK1-2-3-4 etc. Any information on the model names/numbers and whats custom and what isn't would be helpful.