I got my first bass in 1980, then my first fretless (a Fender Precision) about a year later. About three years after that (1984) I discovered Brand X and promptly ordered my first Wal fretless, which got stolen in 1985, so turned right around and ordered another Wal fretless built in Dec 1985 and I took delivery of it in January 1986. About 7 or 8 years later I had Pete (The Fish) at Wal make me a fretted neck for it, and I swap them out occasionally. I sold the Fender fretless Precision a couple of years after I got the Wal, and it seems that TB'er KoaFodera has found it somewhere and is presently in the process of buying it (as evident by the serial number he mentioned in a couple of other threads here on TB).
I still have the Wal, and I just recently put the fretless neck back on it after playing it fretted for about the past two years. As much as I like the Wal, I now wish I'd never sold the fretless Precision.