It is primarily zamac; the handle, adjustment dial and a few other parts are plated brass. No SS. And just to be clear, the Model T was never billed as an all-stainless razor. It was originally to be an all-brass (ala vintage Gillette) adjustable. After the strong initial interest in the Model T Rockwell began "exploring" production of an all stainless version, but fairly quickly dropped the idea as too complicated. They never took any pledges or pre-orders for the stainless version.Not sure, maybe someone else here can comment.
Meanwhile, the original all-brass Model T (which of course Rockwell did take pledges for, and a lot of them) eventually morphed into a mostly zamac razor. Even after this dumbing down of the manufacturing, Rockwell still hasn't been able to produce this razor at scale; their latest update says they have delivered only a quarter of the reported 8,000 razors that were pledged for or pre-ordered. And this is more than three years after the launch of the campaign.