Bill Tindall, E.Tn.
Fixed up a Sargent #4 for son-in-law this weekend. I have a fair amount of experience grinding Stanley blades. Club members come by to get lessons on hollow grinding and in general sharpening. Stanley steel grinds easily, the most easily of anything I have ground. It makes sense these blades would be optimized for the abrasives of that day.
This Sargent blade ground more like a modern steel. It took a long time to grind away the camber and establish a new bevel angle. I set him up with abrasive sheets and in no time he had a blade that made nice shavings on a test piece. Amazing what a useful tool one can find for $20.