[Hadrian Coffin]

Hello,
I was curious if anyone has seen the attached rapier hanger from the Royal Armouries Museum in Leeds up close? I am currently planning a reconstruction. It has been about 6 years since I was last at Leeds... and I do not recall some of the details of this hanger very well.
The point I am curious about is the hardware. It appears in the picture to be of a ferrous metal, which seems odd. Most of the hangers I have seen are latten, with a few silver (or silver plated), and a few pewter. I also know though not to judge the metallic structure of an item based solely on a single photograph, conditions such as lighting, rust, patination, age, etc. can all come into play and fool the eye.
Thank you,
Hadrian