The Die Stamp was used pre 1860 when makers started etching
Split nuts are typically 1875 and before.
Some somewhat sought after saws
Disston Acme 120 (including the thumbhole)
Richardson Bros. No 12
Disston No 12
Disston No. 240 metal cutting saw (No. 240 metal cutting saw. ca. 1945-1950 ) More at Disston Institute
Simonds made saws from 1902-1926
Their early saws had a medallion and etch with the crescent moon in it.
They later had 2 medallions. One said Simonds Saw and Steel and one just said Simonds Saw.