Two days had passed and I was unable to get the pigeon in the chimney to move. I had assumed it was dead. But alas, last night I heard him/her flapping and decided to give the rescue attempt another shot.
I stripped down and actually had to get most of my body into the fireplace. I used a coat hanger that I bent up so that I could get behind the flu. Several attempts finally got some movement and with my other hand I tried to grab the pigeon, the first attempt resulted in a handful of feathers. The second attempt I was able to grab him/her and pull it out.
It was a full size pigeon; I took it out in the back yard and sat it on the bird bath. It sat there for about 30 seconds and then flew off. So I guess it was ok, it could fly, probably a little in shock.