A quick and dirty response: Not sure the contour of the older trailer that the awning is on now is the same as the newer contour, or even the motorhome. The motorhome is a more flat sided unit than the sloping side of the old AS trailers, and still different from the slight bulge center contour used on the '69 and up trailers.
However the Carefree curved arm may fit all, just not sure. I have heard that the curved arm Carefree is no longer available. I don't know if they made different ones over the years.
Now a very personal comment, take it for a grain of salt, but I think Carefree awnings are miserable. I have one on my 20' Argosy and almost never put it down as it is so difficult to do, and even harder to put up and lock in place. I would never put one on my trailer, even if it were free.