I am going with remnants of a fireplace poker.It does look like a honing steel
Part of a handle of a fireplace poker comes to mind as well

Knife sharpener.

A friend identified this as an artillery prick!
We also just visited the Revolutionary war museum in Philadelphia.
Did you know there is not one on display?!
An "artillery prick" (or more accurately,
vent prick or priming wire) is a tool used by artillerymen to puncture the powder charge of a cannon's cartridge so it can be ignited through the gun's vent. This tool ensures that the priming powder is exposed and the main charge can be fired, and it is also used to clear the vent of debris.
