I have a teensy tiny 16/1 Pfiel vee tool that is a honey for fine line work. A honey, until it's chipped or dull.
For honing the inside, I have a strip of brass, 1/16 thick x 3/4 wide x 4" long, filed to fit down into the vee. You can feel when it fits, there is no wiggle. Pat the sides with some diamond lapping compound, lacking that, some valve grinding compound. Draw this thru the vee, especially when sharpening the outside, this helps prevent burrs on the inside.
Every so often, while sharpening, drive the vee tool straight into some endgrain hardwood to remove the burrs.