Gentleman, thank you all. Ian, the model is the Mistral same as yours but slightly enlarged for a project I'm working on. I'm sure that you are right about the boards for the lifebelts, I've seen something similar in the past, but had forgotten all about it.
Tim, using U bolts or wire clamps seems to be a likely answer, unless they did use rope instead of wire for the shrouds. From a modeling perspective I prefer to simulate lashing cords to making miniature U bolts so that's what I'll do.
Thanks again.
Charles.