I have seen some Sailor and Pilot "precious wood" pens that look very appealing. Are they especially fragile? Is the finish hardy? Are they worth buying? On the other hand, can they be polished? I've seen them with glossy and matte finishes and wonder if it's just the photo that make them look like that. Is it a good idea to put some oil on the finish, like you would on other woods? Thanks, Plumon