I have never knowingly passed a CC'er. (Wait a minute... that didn't come out right... Aarrrgggh! Neither did that!!)
In seriousness, since this place has existed, haven't encountered anyone. As has been pointed out, unless they are in CC kit how are you going to know? I can't think a lot of CC'ers commute in CC kit for one thing; even if they own it, they probably keep it for leisure rides.
Maybe there should be a bike or bikebag decoration / removable decal of some kind so that, for those who want to be, CC'ers are recognisable to each other all the time?