There’s a pretty active website for fiberglass fly rodders. Don’t recall the actual address but you should be able to search it.
Lots of good info there on them.
Like most specialty sites, . a vast amount of “knowledge”. And a good bit of it just half vast 🙄..


Greg
"An abundance of information can exacerbate ignorance if the information is of poor quality" Tom Robbins
http://classicsportingguns.com/