I don't know whether the
1959 and
1963 Overlanders utilized the same shower curtain arrangement as the
1964, but if they did, finding an original type curtain will likely be nearly impossible. The original arrangement was a padded vinyl accordian door that was about 3.5 feet tall. The original door on my Overlander was falling apart when I purchased the coach in 1995 so I took what has been a fairly typical path . . . installed a track in the ceiling with dangling slides that had tabs to be sewn into the shower curtain . . . the curtain is a fabric shower curtain that was cut to conform to the curvature of the ceiling . . . and snaps attach it to the rearmost wall while velcro attaches it to the bulkhead wall where the shower abuts the wardrobe.
I wish that I could provide information about a reproduction, but I haven't heard of any. I certainly liked the original accordian door much better than the curtain.
Good luck with your projects!
Kevin