Picked up a nice little D-100 yesterday.
The Institute identified the button as 1896-1917 and the tote as 1903-1921?.
So that puts the panel saw at 1903-1917.
It has a nice apple tote and a ragged tooth little 16" blade with no surviving etching.
It has a full 1" medallion and a 5-nut tote as per a full-sized saw would have--rather than the 13/16" found on backsaws and panel saws as well as No. 16, D-20, D-21, D-22, and D-23 full-sized saws. (It has the distinctive D-100 tote and is clearly not one of these?
Is that unusual?