(FORTUNE Magazine) - I first got into vintage fountain pens as a collector about 1997. My son-in-law discovered eBay and dragged me in. I've been pen doctoring full-time since September 2002, when I bailed out of the computer industry. Right now I have about 600 pens waiting for work. The backlog is a little longer than I like, but the pens come in from everywhere: Argentina, Japan, South Africa. My goal is to do 50 or more in a week. One pen might take ten minutes, others three hours or even several days of working on and off. Working with vintage materials means that I may have to let a repair cure overnight before I can take the next step. More than half of my work, really, is nib work. The heart of a fountain pen is the nib, the point through which the ink flows. If the nib is no good, it doesn't matter how fancy the rest of it is, it's not a good pen. Nibs can be scratchy if they're worn or misaligned. People often want them adjusted for more or less ink flow, or customized for calligraphy. My gross income is less than when I was a software engineer, but I'm happier. I just got a handwritten thank-you from a gentleman in the Philippines. Basically I get my pleasure from making people happy with their pens.