My LED ZEP 2 pressing anything special

First press in the U.S. should probably be a Sterling with interlocking small 'ss'- that's what you typically see on the 'RL' cuts, and presumably on the issues that came out after the RL got pulled. I think Czarivey is right about the catalog number.
If you want help decoding Atlantic deadwax, here's an anecodotal thread on Hoffman. http://forums.stevehoffman.tv/threads/atlantic-atco-vinyl-labels-and-deadwax-what-do-the-codes-mean.285080/
Discogs also has matrix info for a lot of releases.
I think DK is Dennis King, but may be wrong.
Welcome to the cryptology dept'.

PS- probably a late 70's reissue Specialty Records. Scroll down in the
Discogs release info on the album and you'll see it, I think. Note that in the
comments re 'pulling' the RL from the market due to tracking concerns,
discogs says the replacement eliminated the SS because Atlantic itself did
the remaster to tone it down. It may be that your copy sounds better than
one that immediately followed the RL. The anecodotal claims were that it
sounded way too soft. I have a few old non-RL copies, but haven't listened
to them in years. In fact, somebody just sent me another, which may be a
very early remaster, just after the RL got pulled.

It's one of the good sounding releases and definitely worth keeping, but it's 1977 re-issue according to the information provided.
The first US pressing was Sterling mastered. It only compromises to the first UK issue sonically, but outperforms any other re-issues including MOFI, Classic and current. Listeners that value more quiet background will certainly like Classic records re-issue. To me it's missing lots of sound I can hear in first press.

Wow, I stand corrected. Went on Discogs some time ago, and somehow came away thinking this was a first press. The first US is 1969, and as Czarivey says, is a 4 digits. According to my fresh look at Discogs, it's SD-8236. Now I will be out there in the back alley vinyl shops fighting for my copy. Touche gentleman (-:

Fjn- the George Piros (GP in the deadwax) copies should be pretty good- his remaster of LZ1 from the mid-70's is really excellent. Short of finding a clean, unmolested copy of the 'RL' of II (which is expensive even for VG +or- copies and not easy to find) or the first UK plum (which is nutty money), you should be able to find a nice GP for reasonable money. I haven't listened to a GP of LZII (at least to my knowledge) recently, but in the shoot-outs we did of LZ1, the Monarch pressings were also more alive than others, US or UK. So, one possible short-cut is to find a GP/Monarch of II.
Good luck, and let us know what you find in the bins.