Oddly enough I came within a hair's breadth of doing something similar to fabricate a D guard knife for my Confederate impression back in the day. (My inspiration was Chuck Connors' sword from the Branded TV series.)
I already had a repro sword, which rarely saw any use. And I was doing my machine shop training at the time, so I had all the equipment I needed to shorten and regrind the blade.
The idea got kiboshed, when I couldn't come up with a plausible backstory to explain how a rank and file soldier could end up with one during the war. Postwar mods would be easier of course, but I didn't want to destroy a good blade and always have that nagging doubt in my head.