Wow!! Manolo, that is incredibly impressive and I'm glad you showed us the rest of the sword. Obviously an extremely nice commemorative sword issued at some point later to either Captain Wallace or his survivors, and to the importance of that event.
I wouldn't spend a great deal of money on a book that esoteric simply to establish a single reference, especially these days with the computer etc. It was rough in the old days
when we did it that way, ouch!
I would get hold of a reenactment group, who have thier historians for particular units constantly researching those who served in the units. Geneology groups are especially good as well, with Virginia being profoundly thorough. Often it is easier to obtain the capsulated unit histories of the regiments that are more focused and far less costly as far as I know.
My great great grandfather was in the 2nd US Sharpshooters in the Civil War, and I dropped a bundle to obtain a couple of books on this unit.....all I found was a single line where his name appeared. Interesting history, but none specific I could relate to him, and this was a key unit, one of only two known as Berdan's Sharpshooters.
Also I would contact historical societies near the location of that battle. If I recall correctly from that research long ago, my grandfather was there as well. When I lived in Nashville there was Civil War history everyplace!!! and I was often corrected that it was 'The War Between the States' , not the Civil War, and of course the motto, 'Lee surrendered, I didnt' everyplace
History lives passionately in many such places, and I'm sure such records should be reasonably accessible without such expensive books.
As impressive sabre Manolo, well worth the research to pursue.
All the best,
Jim