It's hard to say; it looks like the ones you are referring too are the standard 4" Stockman pattern (like the old U.S. Schrade 8OT), and I think Schrade or Imperial may have made them for Craftsman at one point. They look like the old Frontier brand Stockman patterns I have: a white one (#4432) and a black one (#4434). They are very similar to the Schrade 8OT in size, handle shape, and blade profiles.
I thought the blades on my Frontiers were stainless, until they patina'd to a dark color; I later polished them back to shiny, since they were users anyway. I have a small Craftsman Stockman that U.S. Schrade made for Sears, I think, and it has "Razorblade Stainless" on the blade, like some of my other U.S. Schrades.
thx - cpr