There was no 10.6 PowerPC. Snow Leopard, as originally released by Apple, was Intel only. The project we have now was created years later by non-Apple developers.
I highly doubt the PathFinder devs had any access to early Apple dev builds that may have initially used PowerPC code. And if they did, I doubt they were coding for PowerPC at that point because it would have been known that SL was for Intel only.
In short, I do not believe there are any mythical Pathfinder 10.6 PowerPC nightly builds for the reasons I state above.