It's not fully clear when they started using the "& sons" stamp, but it was almost certainly well before 1817. They posted 'Greaves & Sons' when they moved to Cheney Square in 1801. That's buried in my
gigantic Greaves writeup, but I might wanna add it to the cheatsheet of important details at the end.
There's a possibility that the blade is later than the scales, but it's equally likely that the razor is actually
that old.
You can fix the cut scales with some ground up horn, superglue and hair dye. It's pretty easy to do!