In 2004 we had our original Limited Edition fountain pen with the IPO Diamondback. This was on our Model 01 IPO black pen, with maki-e work by Mr. Nishihara. 

The pen features four mother of pearl diamond shapes, surrounded by lines of platinum, then surrounded again by abalone shells making the larger four diamond shapes. There was an additional mother of pearl diamond on the lower cap front and artists signature and edition number on each pen. 

Nib choices were limited to rhodium covered solid 18K gold in fine or medium.

The price was $975 each and 14 pieces were made. Circa 2004.