I think that thread nicely covers the Peco C55 turnouts, but I don't think that's what the OP was looking for.
On true Peco C80 I'm not quite sure how you'd mate that to Atlas C55 unless you made an adapter out of Peco C55 in the middle, still a bit of a kludge.
I've been mating up various legacy odd-geometry C80's and Peco SL1's to Peco C55 with reckless abandon.