Confusion with xp 2600

I'm looking to make another system and am looking on ebay and other places for a xp 2600. I'm not sure what number tells me wheather or not it is unlocked. I am looking for an unlocked 2600 so what should the number look like and what tells me if its locked or not?! any help would make my day!!

what can suggest locked/unlocked processor is the week number, after the CPU stepping, i.e.:
AXDA1700DUT3C
JIUCB0251

this is taken from my chip the marked numbers tell you when the chip was manufactured, the pattern is like this: yyww, year '02 week 51. AMD started lock their CPUs in week 39 of '03, so look for chips that are as late as possible but were made before week 39, like 0338 or the like. older chips from week 0320 and earlier didn't OC as well as the newer ones. If you can just go to some local PC shops and check out their procs.
just make sure you're getting a barton, you can tell your getting one by the first line of code on the chip:

AXDA2600DKV4D

your help is amazing, thats exactly what i needed!