If memory serves my old butt, I had the panel off years ago and remember the plate constructed of fiberglass or similar material. Definitely not metal. But, I will take magnet out there and see for sure. I could be wrong, but I don't think so. May be able to get better pics of edges.
If someone happened to have a original latch delete made of fiberglass or whatever that stuff is, and would consider parting with it, I would be interested.
Thanks