Here's the technical list in order of release date.
315.114840
315.115440
315.115800
315.115430
315.HD2000
320.51098 / 320.51099
315.115800 was technically the third hammer drill released, but the first two from back in the day were really, really rare. 115800 is the oldest one that you commonly see. It's based off the original ********* 1/2" drill most of us have owned, and as you mentioned it had a metal two-piece chuck on it. I have one and it's a perfectly fine hammer drill.
It was replaced by model 315.115430 which is pretty similar, but was upgraded to a one-piece metal chuck.
The next model was model 315.HD2000. Internally, it is all identical to the XCP Heavy Duty 1/2" drill, but with the addition of the ramp mechanism to the gearbox that allows it to hammer. Shares all the same parts as HD2000: same motor, same awesome 1/2" all metal Jacobs clutch. It was sold as item number 11543X as a kit, and item 11580X as a bare tool.
Due to the fallout with TTI, the few tools left are being made by Chervon. So the TTI-made 315.HD2000 was replaced by 320.51098 / 320.51099. I've never used one, but it looks almost identical to the HD2000. Chervon was probably tasked with manufacturing an HD2000 clone. I doubt there's really anything too different.
Also, you mention not seeing some tools on your "list." I assume you're talking about the small 1/2 sheet of paper that contains a master list of tools, their manuals, and battery packs, that was packaged with some tools. That is something TTI included. It is a handy list, but it must be noted that it contains no Chervon made tools. So there is no Chervon hammer drill listed, along with the brushless, drill, the cut-out saw, the auto-hammer, or anything else Chervon made. The latest version of that list is version "12-11-14 (REV:24)". That includes every tool TTI made for 19.2 / C3.
