I recently acquired an unusual Waterman pen. I know it is in celebration of the 100 anniversary of Allianz but past that i am clueless. The nib is 18k gold and says waterman ideal paris 18k 750 france. I know the bands and clip are gold. The silver metal is not a base metal according to a local jeweler and is some sort of precious metal. It is probably silver or silver plating. the top of the cap has the Allianz logo and around the cap band it say waterman 100 jahre Allianz. When the pen is written with the pen leaks ink between the band adjacent to the nib and the grip. Can i fix this? what kind of pen is this? what is it worth?