Mike asks about the alleged Disston Civil War amputation saw.

Mike,

Disston calls it a 'Saw-Knife' in their "The Saw in History", 9th ed, 1926.

From page 29 - "A tool that is classed with these bone and meat-cutting
saws, and yet is more than a saw is the Saw-knife.  This is a knife with 
double-cutting edge, coming to a point at the end.  One edge is used for
sawing, while the other is used for ordinary cutting."

Below that entry they mention the Subcutaneous Saw for surgical use
as a variation of the Saw-knife.  No pic but described with a pistol grip
and other features that your's is not.

Suppose during the War Between the States, when you took over someone's 
house/farm house, the regimental surgeon might use whatever was at hand if 
his steel and ebony handled amputation saw/surgical kit wasn't unloaded 
from the field trains yet.

Best,
Brian Pennington
Manhattan, KS