How many are there?
I remember thinking about finding them when Fletch Lives came out but I don't think they were ever widely published (if at all) in England.
I think there were 7 or 8 in total.
Looking it up, I see there were 11!
Fletch (1974)
Confess, Fletch (1976)
Fletch's Fortune (1978)
Fletch and the Widow Bradley (1981)
Fletch's Moxie (1982)
Fletch and the Man Who (1983)
Carioca Fletch (1984)
Fletch Won (1985)
Fletch, Too (1986)
Son of Fletch (1993)
Fletch Reflected (1994)