Mine just say USA.  

I wonder if the one I got is the NYC re-issue and if there's a difference if it's not? 

The reason I ask is because I know there are many different versions of the Big Muff Pi.   
If it's from EHX it'll be the NYC re-issue, though that is more of an un-official name for it, really. So on the current (or, since 2000 or so) version, USA=NYC reissue for all intents and purposes. EHX really doesn't do re-issues of other versions/their own past versions the way botique companies might do of, say, the Rams head or triangle versions or whatever. 
Charvel So-Cal (SH6TB/N, killswitch), Jackson RR5FR (TB6/Jazz, Drop C). Joyo pxl pro.
Loop1=Crybaby from hell, Boss PS-5, Seymour Duncan 805 or Green Rhino, EQD Hoof or Earthbound Audio Super Collider. Loop 1 into ISP Decimator II.
Loop 2 (FX loop)-Line6 M9, TC Spark Mini. Loop 2 into mxr 10band. All into a Peavey Triple XXX 212, Ibanez IL15.
Last edited by Maidenheadsteve at Mar 19, 2017,