The white lines on the buffalo handle, are part of the make-up of buffalo horn, its not a fault or damage.
I put a few drops of gun oil on my knives, dubbin or shoe polish on the sheaths, and a waterproof leather spray on the inside of the sheath.
My brother will use nothing else but rubbing a bees wax block over his blades, says it removes any marks, when left for a little time.
A good polish for the handle, is any good car wax polish. Quick and easy and good protection.