Not a great fit, but way better than losing them permanently, I guess! Besides, I'm sure a little trickster magic can smooth out the rough edges...
EDIT: Or maybe he can take the other arm off too for that Daryil Gloves look...
If that arm is stone, than it's gotta be much heavier than his right arm... in which case, his left arm would be a great arm to punch with. Not that there's much of a need for that in this town though...