In thinking of this - you might want to include a sharpening steel into your search.
The handles on those - when a part of a cutlery set - were usually a bit more 'robust' than average - and those are often missing from a set, so you may find one on the loose.
They also used a lot of Stag on those - nice stuff, too - with silver buttplates and end caps.
Sheaths for this type will run the gamut from plain leather - embossed leather - leather with silver throat and tip - and all-metal.
Some will have a belt loop - maybe a belt 'clip' - while others merely depended upon the friction between the trouser's waistband and the body.
Pick a neat, slim, double-edged blade, and you're set for a little dirk of the type that was seen in California, Natchez and New Orleans.
Again - Good Luck.
Vaya,
Scouts out!