It seems like the boat had freestanding mast, there was no standing rigging.
The rig from Laser should fit right in. Or, cheaper version - get an old windsurfing mast and make some sort of sail. Another option - rig from Optimist, probably too small, but it should do the job. Sunfish rig will work too.
s/v NEMO - Freedom 28 Cat Ketch, centerboard