Hi Gerard
To answer your question .
The lines are 1mm shearing elastic.
I sourced some turnbuckles from RB Model. They were the smallest they make. ( in Poland I think)
I made up some connecting loops from 15 amp fuse wire.
I also used some fishing links cut down.
I discarded one end of the turnbuckle and cyanoed the elastic in to the hole.
Hope that is of some help
Regards Alan