I read about it online; it could have been Hutt, but I don't think the reference was that old. It documented test breedings and found fm prevalent in a number of breeds--many of which are not ones where one typically finds frizzled birds.
Glenda has bred frizzles for many years; I know she has written about fm, and seems to strongly believe in its presence; accounting for frizzled birds from smooth parents.
This year is my first experience with frizzles (working on sizzles), so I have some knowledge and theories from books/references, but not from practical experience.