Hi Lewis, not sure if you saw the reply I made on Facebook, but here's what the magnet test revealed:
Bowl is likely raw hide (not magnetic). However, elements of the helmet are magnetic, such as the fin on top, as well as the fukigaeshi (I think that's what it's called - the flap/wings with the mon). The shikoro also is magnetic. On the body, the cuirasse as well as the "skirt" plating (not sure on the name) are also magnetic. The chain mail on the arms is magnetic, but not the shoulder plates.
Thanks for the feedback. Curious if you could expand on it. I'm well aware this is not a highly collectible or museum worth piece (I paid $2500 so I have to be realistic). I also know it's in terrible state. I'm mostly curious to hear if it's authentic or not, and if it's not, what are the tells. Thank you