In review - I am using an Easton EA50 seatpost - the saddle is positioned more to the rear of the seatpost attachment vs being dead center. Maybe a seatpost with a different offset & more center rail attachement position would have helped...
I thought about the B66 with double rails - but it is wider and still recommended for a more upright riding position.
The rail break on right hand rail only occurred just in front of the seatpost attachment. I was able to loosen the attachment & them move the broken rail into the seat clamp area and continue my ride.
I would have then gotten a B17 - but had heard about the cyldesdale Selle leather saddle - so that's what I am using now. I still have a new Champion Flyer if anyone else wants to give it a try.