To help you with the search, these were mostly used on:
- Modern Eagle I
- some ME IIs
- early 513s (all chrome or gold)
- Early DGTs
- several limited runs and PS guitars...
Never really understood their difference to the normal Phase II sets, except they have one more screw point at the top of the tuner.
I think of them as the early experiment to Phase III tuners.
Their life span seems to be from 2004 to 2009ish... From what I understand, you could fit a Phase II set and it would fit fine but you would be left with the hole on the upper part of the tuner empty.
Check out the normal PRS dealers. I have bought a ME I set to replace my all chrome 513 set, since I converted my guitar to mixed style hardware.