There's a place near London that does a full on 4 week course that will teach you what you want to learn. It's about £1480. They are an actual fibrous plaster company with their own workshops, not some government funded training establishment set up to rip off you and the taxpayers. Have a look.
I can fit and repair the stuff but would like to learn to make it, and found their site earlier this year.
https://www.teach-excellence.co.uk/fibrous-adv.php
Hope this helps.
nice one mate just checked it out, only thing is its abit far for me to go as i live near liverpool, i was hoping sumone would let me come along and give them a hand.
cheers though mate