Thanks for the reference Bob. Don’t know why I didn’t think of that myself.
It sure looks like it might be Devil’s Spit. The black areas near the spine don’t bother me as much as those by the edge. I have some brass wire wheels for my Dremel, that I can try out on those once I check out the ones near the edge..
I’ll try honing the blade to see if that exposes any damage under the black. The blade is big enough that I can take off a fair amount of steel and still have a usable razor.
Fingers crossed.