The problem was that my trailer has this old time bumper, and every bike rack available will not fit it. The RV Store in Springfield Oregon is my go to place for my vintage trailer. The man who owns the store has been in business for a long time and will work on my trailer.
The trailer had a custom welded bracket attached to the bumper, and welded stabilizers attached to strengthen the bumper. The nice advantage is that I can remove the rack when I don't want it on my trailer.
I am happy to show it to you.
My 1963 Schwinn is in place, just the right bike for Prairie Flower.