Orange undercoating on '69 Z28?

[JST69Z28]

Has anyone ever seen orange undercoating on a Camaro?  My '69 was originally a Connecticut car and came to Florida in 1974.  As best I can determine, this orange coating was installed before it came to FL.  The whole underside of the car has it, but it was brushed over with some sort of black coating later, probably to cover it up. It has chipped off everywhere, so you see a lot of orange spots, and I am in the process of trying to remove it.  It's hard to get off.  It has what appears to be a red basecoat, then a thick orange coating after that which is not flexible.  Stripper doesn't get it off, so far I have used a needle scaler and finally sanding.  Attached is a photo of one of the front wheel wells with it partially removed.  Just looking to see if anyone has ever seen it before or has any removal tips.   

[Petes L48]

That's "red lead" coating used back in the day, to supposedly minimize underside rust.  As the name implies, it contained lead. Not done at the assembly plant, maybe the dealer or some other shop.   

[camaronut]

If that's red lead for sure.....don't mess with it. I had it on my car back in the late 80's and the body shop owner wouldn't touch my car until I covered it with Rust Oleum or epoxy paint to completely seal it.
 
It's like lead paint in an older home.....kinda dangerous sniffing lead particles.

I would get a lead paint test kit and find out for sure.

[JST69Z28]

Thanks for all the feedback.  I will test it and then determine next steps.