Opty is a Bermuda rigged* yawl, I'd suggest looking at photos of similar yawls.
Also you'll want to do the
standing rigging first, this is the mast stays etc., the
stuff that doesn't move (well usually, it's always interesting when a stay lets go
when you're under sail

). Then the
running rigging the lines that control the
sail position: halyards, sheets** etc.
Mirage kit build on a French modelling site:
http://www.modelismenaval-amiens.fr/voilier-opty/
A nice photo of
Opty from the above site.
Build on Polish forum:
https://modelwork.pl/topic/29208-opty-quotna-faliquot-150-miragehobby/#comment-584399*Also called Marconi rig because the mast looks like an early radio antenna when
rigged.
**The sheets are the lines that attach to the foot of the sail/boom to control its
position port & stbd of centre.