Did the 82 Spectre 1100 use progressive fork springs?

I’m changing the fork oil on my 1982 Spectre 1100 and the oil was very dark and had a plastic smell to it, like something I can’t put my finger on. The fork had progressive springs in it, but I don’t think they came stock like that. 

Has anyone ever seen a stock spring that comes out of an 82 Spectre 1100?