The chrome bar goes across the soft top just above the rear window similar to a W 111 cabriolet or Porsche 356 Cabriolet top. It's one of those early Pagoda details that was later lost. The bar tacks into a wooden bow/crossmember that is directly beneath the canvas. (It's covered in headliner material.)
If your Pagoda was originally equipped with it, it is entirely likely that your chrome bar was removed and never replaced at some point. (When I last chcked, they were still available from M-B, incidentally.)
Lewis Eig recently posted a photo of his former car on this site to show what it looks like.
Finally, the transverse seat is a nice touch. You should be able to pop out the covering on the driver-side. If it was re-done nicely, there's probably carpeting under there as well.
Let us know what you find in both areas.
Douglas Kim
New York, NY
#018260