I have not found any information about when the tang stamps were changed. NYK moved the Walden in 1856 and they introduced Hammer Brand in 1880. I think the early use of Hammer Brand was a blade etch. But when the stamps changed I don't know.
Charles
Early 3 spring 5 blade with oval stamps /HB etch
a stag with the line stamp and HB/ etch
Stunning examples.