I finally figured this out. The trailer is indeed a 1962
Safari, as advertised, but with a much later door. Turns out that nearly the whole right side behind the louver window had been replaced, along with the door frame and a new door. That got rid of the ID plate, but fortunately there were paper records of the serial number.
Last summer we took the trailer on one last camping trip to the North Carolina mountains, then sold it to a nice young couple from Michigan. We originally bought that trailer for $2000, and spent a lot more than that getting it set up for the road. It looked good and handled well when we were done.