I've been a vegan since last September and I had the same struggle deciding what to do with my leather items (specifically my Doc Martens and my leather watch strap). I decided to keep using the items because tossing them didn't seem very vegan either! When they wear our, I'll get vegan replacements. My sister gave her leather items away when she became a vegan.
As long as you aren't buying NEW leather stuff, I think you can definitely call yourself a vegan!