Again, the Disston Saw Company who made this saw called it something entirely different.
Jim Bode--a world renown antique tool dealer who specializes in this type of item--called it something entirely different.
The Director of Research at the Civil War Museum of Medicine called it something entirely different.
These aren't passive observers/appraisers. One is the actual source of the saw in question and the other two are people who specialize in these types of things.
I do not know why the Union Drummer Boy called it what they did. I have bought many things from them in the past and will continue to do so...but that doesn't mean their opinion is infallible either especially when it comes to things on the periphery of Civil War collecting. It is also notable that the saw from their website appears to have a different TPI (teeth per inch) than the one you published which can also the intended use of a saw.
Lord's Encyclopedia was published thirty years ago, and I do not know what provenance led to publish that description. The history of one item in a book does is not evidence that all were used for that specific purpose. Also of note, it looks like the nib of the saw in Lord's Encyclopedia has been altered when compared to your saw.
I understand that there is an emotional connection to the saw since it is part of your collection, and I apologize if I have offended you. The point of the matter is that posting things on an online forum like this opens them up for debate, and there is nothing wrong with that. Without knowing where and when it was found, there is no definitive link to the actual battle or its clean up especially considering that these were still being produced for kitchens well into the early 20th century.