Need help figuring out antique bed assembly

I have an antique brass bed that appears to be missing two identical parts that are used to secure the assembly.
There are horizontal rods that are hidden within the horizontal top cross piece on the head and one on the foot pieces of the bed. The ends of each rod have slots that I imagine are used in conjunction with some sort of fastening clip (the pieces I don't have) that hold the bed together by pulling the vertical tubes toward one another with tension. I have included pics. Does this make sense and do you know what sort of clips may have been employed here?
Thank You\